Garrett has a lot of excellent reading for both tips, research and pleasure. One of the best books which I have ever read is the "The New Successful Coin Hunting" by Charles Garrett. There is a lot of information in the book on places to search. Even today, if I get stumped on where to hunt, I refer to this book.
http://www.garrett.com/hobbysite/hbby_ram_books.aspx
http://www.garrett.com/hobbysite/hbby_ram_books.aspx