I wanted to draw your attention in particular to this excellent post from Sophie Österberg from Wikimedia Sverige -- she's put together a very frank list of mistakes she's made and what she has learned from them. I highly encourage everyone to read the post and add your own learnings, either through commenting on the blog post or through discussion on this list. I think it would be great if we got better as a community of bravely sharing not only what goes well, but what doesn't, so that we can all learn from each others' experiences and not make the same mistakes!
Thanks, Sophie, for the great post:
http://blog.wikimedia.org/2013/02/14/wikipedia-education-program-sweden/
LiAnna