Books on Symbolic Thought??

Teheuti

Symbolic thought is something that we all do all the time anyway. The word "clock" is a symbol. Literally, it is just a combination of five letters of the alphabet. However, this word is a symbol for a certain type of timekeeping device; this is a denotation. It may also be a symbol for promptness and efficiency (such as doing something "by the clock"); this is a connotation.

Subjects such as linguistics would address the issue of symbolic thought, but I don't think this is what you mean.

If you want to learn about symbols, then read something like what Desecrated recommended. Otherwise, rest assured that you are already thinking symbolically, whether you know it or not.
Metaphors We Live By by Lakoff and Johnson is a classic in this approach. http://www.amazon.com/Metaphors-We-Live-George-Lakoff/dp/0226468011/
 

Zephyros

If you're interested in semiotics, Umberto Eco has a pair of books that are very interesting: On Beauty and On Ugliness.