I have Jan as the spellcaster in my party, but I'm really having a hard time finding use for him. I'm a wizard slayer, and I have Keldorn, Jaheira, Valygar, and Jan in my party. While I would hate to give up Jan because I like his character, I can't seem to get magic right... maybe my strategy is wrong, but I'm just really having a hard time. Can someone help me with this.
P.S. this is my first time playing the bg saga.

With your party setup, I would suggest using Jan in a strictly support role, buffing and debuffing. He has no access to necromantic spells anyway, and he's not the best spellcaster or thief.

Ok, is there a better spellcaster out there that I could get?

Sure, Imoen. The only better spellcaster is Edwin, but he's evil aligned.

Edit: Oh, and make sure you give her the point in Intelligence from the Machine of Lum, so she gets more spells and better chance to learn them. And the Robe of Vecna (Adventure's Mart) plus Amulet of Power (Aran Linvale)

You can use some disabling spells like Hold Person/Undead or Web to make the battles easier for your fighters. Where mages really excel is against other mages. Take spells like Globe or Minor Globe of Invulernability, Spell Immunity, and Shadow Door/Mislead as well as protection breaking spells like Breach and True Sight, then you can play a sort of turn-based game with other mages consisting of blocking their spells while removing their protections so your fighters can finish them off. And as Hickory stated, it would be better to go with Imoen or Edwin. Imoen only needs 1 additional point of intelligence to take 9th levels spells, while Jan needs 2.

Actually, this rule is not implemented in the Infinity Engine games (except Icewind Dale 2).

I hear that the Enhanced Edition implements this rule, but if you temporarily boost your intelligence (for example, with a Potion of Genius), you can learn higher level spells anyway, and there is no intelligence required to cast a spell you already know.

>.> Aerie is not amused by your heresy.

^_^

Aerie has the same delay in learning higher level spells that Jan has. On the other hand, Aerie is the only recriutable character that can put cleric spells into sequencers. (Also, note that with some stat boosts and protective spells, Aerie can hold her own in melee.)

Aerie can drop Tenser's Transformation, Improved Haste, and Stoneskin into a blender and serve with a dual-wielded Crom Faeyr / Flail of the Elements. She can do more than just hold her own ^_^

Between Jaheira tanking like a boss, Aerie acting like a googly-eyed Thor, and CHARNAME being a World Blender, BG2 for me is a case study in caster melee XD Minsc is proud.

Actually, Aerie can do well even before you get 6th level spells. Just start by casting Strength (for 18/50 strength) and Enchanted Weapon (to get a +3 mace). Then have her launch a Minor Sequencer with Draw Upon Holy Might in it to boost her Strength to 20 or higher. All this can be done without any magical equipment and without spells above 4th level. (Don't forget that you can cast Enchanted Weapon before resting and not have it wear off. Also. Strength and Enchanted Weapon don't need to be used by Aerie here.)

Also, note that there is a sling that gets Strength bonus to damage. If you can get that, you can make Aerie into a nice ranged attacker without using Melf's Minute Meteors.

Remember that Aerie's THAC0 is better than that of a single-class mage.

If you really want to be ridiculous, have her cast Armor of Fatith, use the Cloak of the Sewers to turn into a rat, and then have her launch a Minor Sequencer with DUHM and Shocking Grasp. After the Shocking Grasp has been used, she is now fighting with normal weapons and has at least 100% physical resistance, possibly more.

Oh, I love Aerie's talents, make no mistake -- she's nearly always in my party -- but I wasn't thinking multi caster class when I posted. Of course, Aerie is unique, and has talents that nobody else can match, but my comment still stands for arcane mage. :)