What is the best web site to research satanic symbols?

Answer 1

There are a myriad of websites out there with information about satanic symbols.
Here are a few I found.
http://www.exposingsatanism.org/signsymbols.htm
http://altreligion.about.com/library/glossary/bloccultsymbols.htm
http://altreligion.about.com/library/glossary/symbols/blsymbols.htm

Answer 2

It depends on what symbols you are looking at, for example some people look at Voodoo symbols as Satanic, Golden Dawn Symbols as Satanic or even Pagan Symbols as Satanic.

This one is a good start

http://www.religioustolerance.org/

Let me know if I can help more.