Once upon a time, I had a bunch of information on my web site about why spam is the scourge of the internet, how to track down spammers, and so on. In the half-dozen years since that time, other people have put up web pages that say the same things, only better. Please check out these sites, for example:

Citizens Against Unsolicited Commercial Email: I wish our legislators would listen to these folks instead of spammers.
spam.abuse.net: What you can do about spam. I was trying to create a site like this, but they did it first, and they did it very well.
www.spamcop.net: Services to automate spam reporting.
Spamhaus.org: Who sends spam, and (just as important) who provides internet service to the ~~scumbags~~ people who send spam. It might surprise you how many of the big internet providers are still quite happy to accept money from spammers and then look the other way. It's depressing, really.
mail-abuse.org: Anti-spam measures for system administrators.