Can anyone help me find a website with a clear explanation of CSS, for someone who's never used them before but is being driven to it and is scared stiff?

I speak basic HTML and make a lot of very nice, dinky websites using Composer and JavaScript (all right, all right, don't all yell at once) and FrontPage but only to add fancy things like nice buttons. I only use the bits of FP that I actually need because I think it's horrible. And I don't have Dreamweaver or anything posh like that.

Thanks for your help.