ThaumCraft is a Magic/Adventure Mod, kinda like Tinkers construct in some ways. Edit
Thaumcraft is a mod which allows you to use the magic around you in the form of "vis" (pronounced "vee" or "veece") to perform different tasks and create fantastic items. Unlike earlier versions, there are six types of basic vis which can be stored in your wand, the amount of vis you can carry depends on two different parts of it, the core and the caps. The core can be made of various items, like greatwood, obsidian or silverwood; and the caps can be made of different metals, from iron to thaumium. Try the Thaumonomicon! It has tons of info, and can help you get started easily.(No body gets mad if you bring it to your inventory from TMI, singleplayers.)
The Thaumonomicon Edit
The Thaumonomicon is a dense tome of arcane and alchemical knowledge, both acquired and yet-to-be-acquired. Whenever Research is successfully completed, and the resulting discovery used, the information learned is added to this book. The Thaumonomicon is the single most important tool a player will create for themselves in ThaumCraft, and (should) last right up until the end of the game. Not only is it the repository for all of the player's completed research, it contains hints for progressing towards more advanced research. Research can be difficult to use, however, because you do not see what elemental propeties are needed, so you are forced to use trial and error.
Crafting The Thaumonomicon Edit
Make a normal bookshelf, (Bilbiocraft ones will not work) And then a Iron Capped Wooden Wand, with 2 metal caps, at the bottom left and the top right, (made from 5 iron nuggets in a helmet shape), and a stick in-between the two. Then the hard part: Right click the bookshelf with the wand in hand.