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Sign up for Google account and you'll have a nice collection of collaborative tools to make your group projects easier to manage.
Google Docs make collaborative writing and presentations easy to use. You can use Google Docs to keep track of your meeting notes and agendas, your group goals, and other resources. Google Docs allows you to simultaneous share spreadsheets, presentations, and written documents to make it easy for everyone to contribute to the work. You can also use the "revision history" to see whose added and edited the work.
Groups for online classes need to meet, too. Even if you can't all meet in person, GTalk can be the next best thing.
Email is great, but it can be confusing to keep track of all your group work email. Instead, try setting up a Google Group. That way, you know that everyone is included in every thread.
What other Google product help you with your group projects?