Is there a good site or book concerning the origin and meaning of symbols? I mean such things as & (ampersand) and + and =, and symbols for the signs of the zodiac. I once had a tiny dictionary that had a short list of symbols at the back, including one for 'per', which I have never seen used.
Click http://www.symbols.com/index/wordindex-a.html
for an excellent symbols website. Once there, click on the appropriate letter, scroll down to the word you want, then click on the blue number beside the word. For example, on the opening page - the letter 'A' - scroll down to 'Ampersand' and click on the figure. You will be offered an example of the symbol and some explanation of it.