Pooks - either could work you know - used or new...

A quality LBS should not be selling suspect used bikes. To me it is a matter of personal preferrence.

As a rank beginner though the appeal of a new bike also has to do with the fact that some LBS's, like the one I go to, give free lifetime adjustments on new bikes. So that is certainly comforting and appealing.

More important than the bike of course, are good riding skills, proper equipment (helmet, gloves, shorts), and common sense.

Besides, your friend has you - a wealth of knowledge at your disposal