[rcollyer]

Another method for checking your understanding is to work through the worked out problems in the book and any proofs it may have, too. (Most of the value in a proof is in the techniques used to prove the result.) Work through them yourself, trying to understand each step, and attempt to do the problems in the same way. At first, justify each step you take, don't try to skip the "obvious" steps. Again, this isn't a perfect substitute for an instructor, but it can go a long way towards your goal.