Heheh, okie then. 2nd Edition Netheril campaign just has me a biiit excited.
Gazzien, Arcanist is basically just a modification to the Mage class. There's like four tables in the Netheril: Empire of Magic boxed set that cover the modifications. To sum it up: you no longer memorize spells, but spontaneously cast any spell you know, using 'arcs', which are equivalent to spell points, each worth one spell level, thus a 3rd level spell costs you 3 arcs to cast.
Arcanists are also all specialists, but not in the traditional schools. There are only three schools: Invention, Mentalism, and Variation. Invention creates/destroys, mentalism affects the mind, variation alters things. At least, that's the quick description. There's a listing of PHB spells and how they fit into the three schools in the book, but it's kind of annoying to read because you have to cross-reference that table with another table that gives the Netherese names for spells. Maybe I'll write those into a spreadsheet while you guys are reading up on the basics, so everyone who decides to play a spellcaster can reference that.
Anyway, you specialize in one of the three schools as your major, another as your minor, and you're prohibited from learning spells from the third. If we wind up with multiple arcanists in the party, it would probably be a really good idea to make sure we have different majors, at least, because you can only research new spells from your major. You can learn and cast any spell in your minor (up to normal limits, and based on a learn spells roll) but you can't research new spells that are deemed to belong to the minor, so someone who doesn't major in mentalism can never research a new mind control type spell. But if they minor in it, they can learn it from whoever researches it.