Best info so far is on
EQ Traders as Larth said. I have found in-game books to be delightful examples of creative writing but little else. I haven't even bothered buying the books available in POK.
For what it's worth it looks to me like Alchemy has gotten an upgrade. What used to be called potions are now far more varied and versatile. For quick reference, and since I'm on the subject :-) , I'll provide links copied without permission from EQ Traders;
Distillates are the alchemy potions that have effects like curing disease or poison, or regeneration
Elixirs and Effusions are statistic buffs like those that can be cast with spells. Elixirs improve your performance stats (strength, wisdom, charisma, etc) while effusions improve your resists.
Philters, Mists and Essences are the miscellaneous potions, those that have various effects which don't come in a patterened order of strengths. Philters and mists have the effects most familiar from alchemy before the Prophecy of Ro revamp, like see invisibility, teleport, and the all important sow (spirit of the wolf). Philters only affect the drinker, while mists affect the drinker's whole group that is in range. Essences are the same illusions we knew before the revamp, with the same names even. The recipes have just changed a bit.
Suspensions are the thrown alchemy potions. These have damaging effects like
snare (YAY!), blindness, or damage over time.
Tonics are Potions with focus effects. These can either reduce the mana it takes to cast a particular type of spell or increase the duration of the spell once cast, just like the focus effects found on gear.
I hope that helps. I found some of the vials on the Alchemy vendors in POK. My Foldable Bearskin Medicine bag has been renamed and since potions now stack I guess it's just another medicine bag. Oh well, at least new Heyokahs won't have to slay hundreds of bears to get a Grizzly skin as I did.
It looks like we will be able to make some really useful stuff, if only for our alts and friends. As far as finally being able to make some plat off Alchemy? Ya think? ...... Nahhh. On a personal note they lowered the trivial on Gate potions and cut the price of Heliotrope by more than half. I can now make them and won't be murdering my rogue anymore to get him back to POK. It might also be kind of cool to lay one on a group member when we wind up far from home. We'll see what develops.