When I was first learning to program I submersed myself in Open Source as a way to improve my coding chops whilst at the same time learning how to work effectively with other programmers. This was mainly down to the influence of two developers, turned managers at Google. Brian Fitzpatrick ("Fitz") and Ben Collins-Sussman.
Ben and Fitz have strong roots in the Open Source community and worked on the team that brought Subversion into the world.
Over the past 5 years Ben and Fitz have given a number of talks about how to effectively manage Open Source projects and how to play well with other developers. Watching these talks on YouTube really inspired me to become a better programmer, and a better team member. Everyone that works on Open Source projects, or just works with other developers in general would really benefit from watching some of theses talks. I've put together my favourites here.
Welcome to the Ben and Fitz show.
Open Source Projects and Poisonous People
The Joys of Engineering Leadership
Do you Believe in the Users?
The Myth of the Genius Programmer
Programming Well with Others: Social Skills for Geeks
The Art of Organizational Manipulation
Ben and Fitz recently wrote a book called Team Geek that embodies a lot of what they talk about at conferences. It's a great read and I would definitely recommend picking up a copy.