Tommy, Unlike others, I would say go ahead and buy some of the coins you're interested in. If you make some mistakes, you'll realize it later on. Most everyone makes mistakes at the beginning. I have sold some of mine for losses but hey, it's a learning experience and collecting is a work in progress by definition. Enjoy it! There aren't any great Walker books. Ambio's is okay and the Fox book isn't much better. Still worth reading both.
Tommy - a short set of Walkers is a fantastic set. I personally am collecting them in 65 (with the exception of a couple of key dates, the 65's are very affordable). A 65 will hold its value and appreciate more than a 64 (as someone else said). The thumb issue is very complicated - just like Full Bell Lines on Franklins, some dates come well struck, others are very weak. You have to learn which ones are which, and can then assemble the best set possible. And yes, looking at thousands of coins is an absolute must. Its not a job - its a hobby. It should be a pleasure to look at a thousand accurately graded coins. I mean, you don't have to keep count, but the point is look at as many as possible to try and learn how to grade accurately. You will save yourself loads of money and trouble down the road. Even for a short set in 64, you are still talking about hundreds, if not thousands of dollars. If it were me, I would certainly want to know everything I could about something before spending that kind of cash.