There's this incredible detailer in Columbus, Ohio named Todd Cooperider. He runs Esoteric Detailing, and he was named among the top detailers in the nation by Auto Week magazine.

At any rate, he has some really good "how to" articles and tips on this page:

Esoteric Professional Detailing Articles

Yes, it's ad supported, and the site this is hosted on sells the products he demonstrates. But the tips are great.

I have no affiliation with this company or Todd, other than being a fan of his work. He's also a super-nice guy.