Wilmott.com - Paul Wilmott's page.
Wilmott is the author of many quant books. The site contains numerous
quant based magazine articles (but I haven't signed up to see these!)
as well as a messageboard and a jobs page.
This is a major website for credit derivatives papers, which can be
viewed for free. There are several hundred at the moment. The few papers
that I've looked at have been very complicated. I have however understood
the introductions, and they are quite useful for getting a quick overview
of financial products.
This is a newer website with careers information for those in the field
of quantitative finance.