Good and bad choices

As a starting point for group communication, I chose to use Google Groups. It is used by several other groups that I take part in to great success but now we are using it for real, there already seem some limitations. For example. We will have a document (currently under Google Docs), which will hold information about the various aspects of the project, who has taken on that role and what their progress is. Of course this has to be editable by everyone in the group but locking needs to be applied to make sure the document isn't edited by more then once person at a time. I'm sure Google Docs handles this very well but there is no elegant way of integrating this document into the Google Group. It seems Google write great web based utilities but integrating them is not so great.