[Indemaijinj]

Well, there is only one class that I would not recommend to a newbie and that is the monk. They are weak in the start, but totally overpowered in the late game. Not good for the learning curve.

Here are my consideratíons on the classes:

The warrior group:

The warrior group is made up by the fighter, the ranger, the paladin and the barbarian (and to some extent also the monk, but that class is kinda weird).
Warriors are good at whacking people with weapons and enduring being whacked themselves. Thus they will usually be the ones to stand at the front line dealing blows though they can also be good ranged fighters peppering the enemy with arrows (the NPC Mazzy Fentan is a prime example of this).
Warriors can put two proficiency "dots" in a weapon getting extra skill with it.
Warriors gets many attacks per round and they can reap the benefits of a constitution above 16. If their strength is 18 they will also get a seperate stat indicating some kind of bonus. If this stat is high (or 00) this will greatly increase your fighting ability.
Playing a warrior much of the game will revolve around "upgrading your hardware" getting better weapons, armor and various magical accessories.

Strength is of great importance to warriors since it decides your melee skills and damage. It is slightly less important for "archer" types. Strength will also decide how much loot you can carry around on you which is also important for fighters.
Dexterity is of great importance because it decides your base armor class.
Constitution is important because it will give you extra hit points.
While intelligence isn't of any importance to fighters it is good to have it at at least 10 (can read and write) since you will not be able to use some items (such as resistance scrolls) otherwise.
Wisdom is of no real importance.
Charisma has some influence of who strikes first in a round of combat and also decides how much items are gonna cost you in the game. But since you can get a ring that boosts your charisma to 18 very early in the game people tend to prioritise charisma lowest.

Fighter.
You can't go wrong with a fighter. Besides the usual warrior perks they have the specific ability to put five proficiency "dots" into a single weapon thus becoming really fearsome with it.
When creating your fighter you need to make some decisions on what weapons you want to use since you will be using many "dots" on few weapons to reap the benefits of being a fighter. You will probably also want to know whether you are a single wielding, sword and shield, two handed weapon, or dual wielding person.
Fighters can use all kinds of weapons with equal skill.
One of the prime weaknesses with fighters is that besides their fighting skills and toughness they have little else in terms of abilities. They are at the mercy of spells, traps and various special abilities. They do make up for this somewhat by having good saves and many hitpoint, but sometimes this isn't enough when spells are flying. Therefore you will need to stock up on items that grant resistances and immunities against a wide range of hazards.

Berserker (fighter kit).
What seperates a berserker from a normal fighter is their ability to berserk. In this enraged state they will be able fight better, but most importantly they get some of what the fighter otherwise really lacks: Immunity! They will be immune to all mind-affecting magic (this is really cool) and level-drain (a life saver) and even the mighty spell Imprisonment!
Given their abilities survive all kinds of assaults and their inability to get any skill with ranged weapons their role will almost always be to stand at the front lines recieving blows while laughing away at their lack of effect.

Kensai (fighter kit).
This kit is weird. This is basically a fighter who have sacrificed his ability to use any kind of armor (not even bracers or helmets) in order to get exceptional skills with his melee weapon. Due to some strange effect (jokingly called "bulletproof nudity") the kensai still get some semblance of armor due to his ability to dodge blows more freely or something other.
A kensai is able to dish out extreme amounts of punishment with his weapons, especially when using his Kai Shot but is very fragile due to his lack of armor. A kensai often needs some other warrior to take the blows while the kensai stands right behind and lands them.
Since this is one of the few ways to get a cool armor class for a kensai Dexterity is even more important than with a regular fighter.
Kensais are most often dualed to mages.

Wizard Slayer (fighter kit).
Wizard slayers have sacrificed the ability to use any magical items besides armor, weapons, shields and such. Instead they have got special skills in fighting spellcasters, being especially good at breaking their concentration and such. A wizard slayer is a bad class to start with for a newbie since they are unable to use the often life-saving healing potions.

Ranger.
A ranger is a warrior with a special link to nature and some druidic training. Besides the usual fighter abilities they can do a bit of druidic (a variant of clerical) spellcasting and has special powers over animals. Rangers also start with two "dots" in dual-wielding for some reason or other. Rangers are also good at hiding themselves, but cannot do so if wearing metal armor.
In most ways playing a ranger will be similar to playing any other warriors.
Rangers must be good of alignment and they lose all of their special abilites irrevocably if your reputation goes too low.
Rangers can benefit from high wisdom due to their spellcasting abilites.

Beast Master (ranger kit).
These rangers are even more attuned to nature. They flatly refuse to use any armor or weapons made of metal and is thus hindered to only wearing leathers and hides and wielding clubs, staves and bows. Be warned! Finding decent warrior equipment for a beast master can be a considerable pain in the nether regions.
Beast masters gain the abilities to cast a lot of summoning spells, who would otherwise be to high-level for them. This is rather nifty, but their only real advantage.
They can also get familiars.

Stalker (ranger kit).
This kit emphasizes the sneaky part of the ranger augmenting it with the thief ability to perform backstabs for extra damage. Stalkers also gain the ability to cast some wizard spells, mostly dealing with dispelling things.
Stalkers are a strange all-round kit who combine the warrior virtues with those of a thief and a mage.
Due to their sneaky nature they are only able to use the armors that thieves use (leather and such). This makes them a less front-line worthy class, though they should be able to stand some punishment now and then.
Due to their lack of heavy armor and their thieving skills dexterity is of prime importance to them.

Archer (ranger kit).
This ranger excel in the use of bows. You need just take along the NPC Mazzy Fentan to realize that this is a rather powerful specialization (note Mazzy isn't a ranger archer). Archers can put five "dots" in all kinds of bows even though they aren't fighters.
Since using missile weapons make you much easier to hit in melee archers are not front liners. They should stick in the back and rain death at enemies instead. This also makes their inability to use plate mails less a drawback. If you really need them up front, however, you can easily shift out their bow for a melee weapon and count on them doing some damage. They are warriors after all.
Since they are using ranged weapons all the time Dexterity is the most important ability for them.

Paladin.
Paladins are lawful good stalwart defenders of all that is right and true. They add some priestly abilities (spells, turn undead) as well as some extra healing abilites to the standard warrior abilities. They are even better at resisting bad effects due to their higher saving throws.
Paladins need high wisdom and very high charisma for some reason.
Paladins are good basic front-liners but you will need to take the "good" path through your adventure (this is not that big a drawback, since the "good" path is usually also the best path to take tactics-wise).
Paladins can use the most powerful weapon in the game (a two-handed sword).

Cavalier (paladin kit).
A cavalier is a really good kit for starters. They are warriors who get special bonuses against some of the most badass monsters in the game: Fiends and dragons.
Their true power lies in their resistances, however. They are immune to fear and poison and can cure other party members for these effects too. They are also resistant to fire and acid. A good solid choice for a front line warrior.
They are unable to use missile weapons, but if you stick them up front this will not hurt that much.

Undead Hunter (paladin kit).
An undead hunter specializes in combating undead. Again their real strength lies in their immunities. They are immune to hold and level-drain effects, both of which are very dangerous.
They are unable to heal people by "laying on hands". But if you have cleric or druid along for healing this is not much of a disability.

Inquisitor (paladin kit).
Inquisitors specialize in dealing with evil spellcasters. They lack the clerical abilities of other paladins and have no healing abilities whatsoever.
Their immunities are again their strength. They are immune to charm and hold. Their special abilites are, however also good. They are able to use dispel magic and true seeing. Two really neat spells for ridding the area from hostile spells. An inquisitor can do a great job at putting the hose on enemy spellcasters.

Barbarian.
Barbarians are a weird kind of warriors, but easy to play. They have the ability to enter a rage, though it is not as powerful as the berserker rage (it hurts armor class and doesn't protect against Imprisonment). The rage still protects against all mind affecting effects and level drain so it is still awesome. Barbarians are a bit sturdier than your average fighter since they have the largest hit die in the game (12 sided) and gains resistance to physical damage, you head me right: Physical damage! They are also faster than your average character allowing them to get quicker to a hot spot. They have a little disadvantage in the fact that they can't use plate mails. Still they make excellent front-liners.

To sum up the warrior classes:

Fighters: Good at hitting and hurting people.

Rangers: If you want some extra flavour on your warrior.

Paladins: Good for immunities and healing/protection spells.

Barbarians: Good for suffering extreme amounts of damage and still look good.