First off - fair warning: 3.0 is a broken system. There's a reason they released a 3.5 edition to patch it up several years ahead of what they were planning on. In a one-off game, this shouldn't be as big a problem, especially if the players don't know the system very well, but still ...
Anyways, if you're looking for a scholar, cleric or wizard is the best way to go. Wizards are definitely more suited to scholarly pursuits - their high Int is good for Knowledge skills, and all Knowledge skills are class skills for them. Also, depending on your level, there's a prestige class in the 3.0 DMG called the Loremaster, who takes scholarliness to the max.
If you wanted to do cleric, try a cleric of a deity with the Knowledge domain (which also fits with the scholarly theme). I'm not familiar with Forgotten Realms deities, so I can't help you on which deity to pick.
If you're looking for a wizard, I might suggest picking up Tome and Blood, the wizard/sorcerer supplement. For a cleric, Defenders of the Faith would do the same thing. I'd hesitate to buy one of those for a one-off game, though, even at half price.
