huge fan of Mike Kojima and Dave Coleman. They are extremely technical writers and I have always strived to be like them over the years of toying around in the journalism world. My hat goes off to those guys for everything they do and did back in SCC days. Eric Hsu and Sarah Frost are up there too. Very good content on that site.
As far as other "good" sites. I like Speedhunters but it' not usually very technical. Good stuff though. They really need to come out with a magazine.
I like timeattackforums.com, Grass Roots Motorsportsports web forum is good as well. Raccar-engineering.com is another good site as well.