Welcome to MR, Rob, and congratulations on your new iRiver.
I found a
MR thread about the iriver that may have some useful information.
Also, just in case you hadn't seen or heard of these sources for ebooks..
MR has free ebooks that have been beautifully handcrafted by some very dedicated MR members. (I believe that they are better formatted than Google books.)
ePub format
Free ebook sites
feedbooks.com
manybooks.net
Free and for purchase ebooks
smashwords.com
baen.com
Plus Baen has a
great free library
Have fun exploring the forums and ask if you have any questions.