Hi there, I am halfway through BG2 with my Druid, and it's not a bad character to play. I started her in BG as a fighter, dual classed at level 5 to Druid, and then took her all the way to BG2.
Minor Item Spoilers below
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Good weapons.
I would put as many weapon points into staves and 2 handed fighting style (don't even bother with slings) as there are just so many good staves out there. As a druid you will get the Staff of Thunder and Lightning (+2) with your stronghold quests early on, plus there is a clerics staff (+3) which is easy to find, and the Staff of Rynn (+4) is a must as soon as you can afford it. Later (ToB only I think) you can get the Staff of the Ram (Thaco +4/ dmg +10) which is unbeatable. Otherwise there are the staff of earth, staff of fire and rod of smiting which are all useful to have on odd occasions and the staff of the woodlands+4, (which I think should have been a Druid stronghold quest reward as it turns up too late in the game to be much use)
If you fancy a 1 handed weapon, there are a few good clubs out there (you get 1 from the stronghold again) but I think the best is the one you can buy in Trademeet ~ Blackblood+3 +3 acid I think, as this is useful for finishing off trolls. Or buy the staff mace as this allows you to use the odd shield if you are dual/multiclass (I found the shield of Balduran very handy later in the game
Various fancy Spears, Scimitars and Daggers are also available, although none really sprang to mind as a must have weapon for me, most only being average +2 types.
Spells
As for spells, chaotic commands. Ironskins and Negative Plain Protection are always useful, plus summon insects, insect plague and creeping doom are great offensive spells against any spellcasters. Call lightning is very effective outdoors but can't be used indoors (or in the tree of life at the end, which is odd???)
Summons.
If you have the Weimar mod, then the Greater Werebears of cheese are fun to watch for a while, but most other summons are mainly useful as distractions or to soak up the worst spells the really heavy guys chuck at you.
Have fun.