im making a fighter and im wondering if i should put some points in intelligence... ?
or boost strenght , dexterity , and constitution instead ?

Boost STR, DEX, and CON. However, try not to totally ignore INT and WIS. I believe that there are some creatures in the game that actually drain INT points. If they drain all of them, then you're dead. Also, the higher your WIS, the less susceptible you are to mind-affecting spells and illusions.

I think INT is also important should you decide to duel (for human only) your fighter into a mage. INT also determines the amount of time when you are imprisoned under the mage spell "maze".

When you roll your character, it's worth re-rolling untill you get a total of at least 85 stat points. You can get 85 with less than 50 rolls, and if you want to roll about 200 or so times, you might be able to go as high as 94 total stat points. This will give you 4 18's and 2 10's, definately worth waiting for! Good percentile strength is nice, but not essential, there are items that will take your strength to 19 - 20.

For a fighter accept no less than 18 Str, Dex and Con, and then decide what you want the rest to be. I really like paladins, so I usually throw it into charisma, but I also like multi-class fighters too, in that case a wizard needs 16 - 18 INT and a cleric definately likes 18 WIS.

Cheers