Also relevant, this free and very accessible book from O'Reilly http://www.oreilly.com/openbook/osfreesoft/book http://www.oreilly.com/openbook/osfreesoft/book

Also relevant, this free and very accessible book from O'Reilly http://www.oreilly.com/openbook/osfreesoft/book http://www.oreilly.com/openbook/osfreesoft/book that explains the history and caveats of most open source licenses.