Depends on what you're looking to get out of the book...
If you want super easy super awesome self working tricks I'd tell you to grab card college light (CCL) or the Encyclopaedia of Card Magic (EOCM) .
Both are fantastic. For the money you get far more with the EOCM but the quality of the content in CCL is very hard to deny, it's powerful stuff.
Books like Expert Card Technique (ECT) are brilliant but require a little more than just a foundation to truly wrap your head around and even when you do, it takes years of practice to make each of these sleights truly worth your while.
So, practice the sleights from ECT and start performing some other material from the books above in the mean time. When your done performing each effect once, odds are you'll be pretty good at some of the sleights from ECT and you can adapt the other effects to be pretty crazy.
Just remember, just because something is easy does not make it any less powerful. It's all in the performance.
B.
