Forgive my newbishness but I have a question to ask about teamwork...mainly because I stink at it. Most of my projects up until this point have been solo so I have a very limited experience with teamwork. I did make graphics for a game that was being developed by several people, but that was completely different than programming with several different people.

Right now I'm working with someone else on an indie MMO along with a few other team members. I've already made some pretty stupid mistakes, (like rewriting EVERYTHING) so I have two questions for you guys:

1) What are some of the most common mistakes that people make in a team environment and how can they be avoided?

2) How can the structure of your program be altered to allow for multiple teams members to work on different parts of the program at the same time?

P.S. Is this the right stack exchange site for this type of question? (if not, where does it go? Thanks)