Congrats on the purchase, nice looking ride...
Check the links below for PDF version of 2007 M Owners Manual, unfortunately they don't have an '08 version yet at this link.
http://www.bmwsections.com/docs/
Also there is a download section here at the site that I know has an M supplement to the owners manual.
http://www.zpost.com/forums/forumdisplay.php?f=82
I'm sure someone with an M may have a link to an '08 version.