Brent Simmons: Notes on being a nice person online who sells software.
Some good advice from a guy who's been selling software for a long time. My biggest peeve that Brent covers is "complaining about other people and things". I know I do it myself from time to time, but I always feel horrible right after I click the tweet button or whatever.
Daniel Jalkut continues the idea on his site: The Oldest Trick In The Book.