After I wrote my review of the book “Microsoft® Office 365: Connect and Collaborate Virtually Anywhere, Anytime” by Katherine Murray, Microsoft made it available for free in PDF format.
After it was promised that additional formats will be available soon, you can now download the ebook in the formats .epub and .mobi (the latter is the format you need to read it on your Kindle; most other devices should be able to read at least the epub format): http://blogs.msdn.com/b/microsoft_press/archive/2011/09/23/free-ebook-microsoft-office-365-connect-and-collaborate-virtually-anywhere-anytime-now-in-more-formats.aspx