In many cases the tooltip is a little vague. Information provided on what the skills do is a summary of the tooltip, rather than actual ability use. All skillbooks require level 1 in each of the two skills needed to make them, except Corrosive Spray which requires level 2 in each. All skillbooks will be of the elemental element except for Blood Rain which is necromancy and all infusions which are summoning. This is a quick list of the skills you can acquire this way. This only appears to work with an elemental and non-elemental skill book. Skill Book Combinations If you combine a skill book with another skill book then you get a brand new skill that requires both classes. So you might want to save these materials until later on so you can make higher level weapons either to sell or use yourself. Be aware, the weapons created will be at the level your character crafting them is currently at. That being said, know that if you ask the Doctor if she has potions she teach you the recipe for minor Healing Potions.
If having things scattered all over the place annoys you, then save all the recipe books you find, but DO NOT read them until you are ready to begin crafting. Note: Try to avoid crafting anything until near the end of Act 1 if you like your menues looking orderly.
