If you want the best picture book then get Richard's. It has very good quality pictures. It is a bit pricey but so is this hobby. In my book you get exactly what you pay for and Richard's is the best hands down.
I think Bill's book has more strikes in it than Richard's and makes a very good combination. I have Richard's Master and 1 of his updates. I am on my third book of Bill's.
I started with Art's and it was helpful but was very confusing because he didn't alphabatize the casinos and I don't live in Nevada and had no idea where to look for the casinos in which cities. I think it is a big mistake he hasn't changed his format. Just my opinion of course.
Rog