Rule #1: No publishers. Publish the book yourself.
A publisher usually has marketing and distribution options at hand that you could only dream of.
Rule #2: No 3rd-party sales channels. No Amazon/Kindle, iBookstore, etc.
If your goal is to spread it as much as possible than you've got to use any possible option.
Rule #4: Publish as a PDF. Optionally also as EPUB, depending on topic/audience. No dead-tree version, please.
To sale thousands of copies you should try to offer a diversity of formats. While there is no reason why you should not print the book to sell to those who prefer it, a "dead-tree" book is no ebook and thus the submitted post is correct that you should avoid that when trying to sell your ebook. I guess.
Rule #5: Price high. Price for the value you provide, not for what feels right.
To sell thousands you should probably not use a high price, but price rather low.
I pulled my answers out of the air just like madrobby. Yeah, I am getting sick and tired of these marketing fluff unscientific best-practise posts. Same level as the usual life improvement blogs for me.