I can't claim to have done much illegals research yet, so I'll let others answer your question, but one place you can learn a lot is by reading Gene Trimble's articles on David Spragg's website:

http://www.marlowcasinochips.com/links/genetrimble/genetrimble.htm

I wrote a story for the club magazine about my only illegal search, which tells you exactly how I did my research. Here's a link:

http://www.markcotton.com/c&c.htm