Dream Symbols
There are probably hundreds of "dream dictionaries" on the market. Sometimes I collect interesting specimens, more often I ignore them. But they do come in handy to jog the mind in different directions. So here is an assortment of reference guides, but by no means a complete listing of anything! As with most things, let your intuition be your guide.
The Penguin Dictionary of Symbols (Dictionary, Penguin)An Illustrated Encyclopaedia of Traditional SymbolsDictionary of Symbols
The Penguin Dictionary of Symbols (Dictiona...
by Jean Chevalier
$15.64
This is my go-to book for learning more about symbols I meet in dreams. Excellent resource.
An Illustrated Encyclopaedia of Traditional...
by J. C. Cooper
$13.57
Another really useful reference book on symbols, richly illustrated, with brief and often surprising entries.
Dictionary of Symbols
by J. C. Cirlot

I don't like this one quite as much as the others, but it is still a good reference.
Dream AnimalsThe Secret Language of DreamsDream Symbols
Dream Animals
by James Hillman

Fabulous essays by psychologist James Hillman about experiencing animals in dreams.
The Secret Language of Dreams
by David Fontana

Nicely illustrated, with lots of info on working with dreams as well as a good summary of many dream symbols.
Dream Symbols
by Sara Phillips

This is a large format book particularly suited to younger people. Somewhat general, but good as an intro.
Dictionary of SaintsIn Your Dreams: Falling, Flying and Other Dream Themes - A New Kind of Dream DictionaryThe Macmillan Illustrated Encyclopedia of Myths and Legends
Dictionary of Saints
by John J. Delaney
$10.85
I'm not Catholic either, but you'd be surprised how many times names in dreams have some link to saints of the same name.
In Your Dreams: Falling, Flying and Other D...
by Gayle M. Delaney
$12.74
Covers common "dream themes," variations, and suggestions of how to work with them.
The Macmillan Illustrated Encyclopedia of M...
by Arthur Cotterell

Can't remember the difference between Hades and Helios? Legba and Lugh? Check here first.