Hi Mike,
You are correct about the two price guides we have for our hobby. But there should be new editions of these two GREAT books published in the next several months. Just keep you eye out for the release dates. Also Archie Black has a great reference book for the AC chips which he does a wonderful job on. There are also books available for other ares of the US. Not to mention books for ashtrays, slotcard, silver strikes and what ever casino related stuff you might want to collect. Until you figure out what you want to collect it is probably a good idea to ask on this board the opinions of others. Plus a mentor would be a great idea in your case.
Hava Good One,
Richard