Thaumcraft Three is a mod that focus' on adding a reasearch system that allows you to obtain advanced tools and items. As well as adding some fancier toys like Golems that can run a farm for you (and much more than just farming!) and some new fancy mage armor!
First you need to make a Wand of the Adept. (There are more advanced kinds of wand later on!) You must have a stick, a gold nugget, and a shard of any type. You must then place them in a crafting table in the arrangement pictured on the right. Remember that this can be a shard of ANY type not just the one shown in the picture below.
Next you need to get yourself a Thauminomicon!
Once you have a wand you can go up to a bookshelf and right click it with the wand. The Thauminomicon will then appear. The Thauminomicon is a book that records all your completed reasearch and recipes. You can open it at any time by right clicking when it's in your hand. You can add your discoveries by right clicking on the discovery scroll. The Thauminomicon will then record that discovery and all it entails. But, before you can make any discoveries you will need a reasearch table. A reasearch table is made by placing two tables next to each other and right clicking on them with scribing tools.