Welcome to MR, jag88
It sounds like you have already found
Calibre to manage your library of DRM free books and Kovid, the creator, frequents the forums here. Have you visited the dedicated
Calibre forum to check for book loading help?
There is also the
Sony Reader Dev Corner, if you want to explore enhancements to your 505. Be careful, as it makes a difference which firmware you have (US or UK).
MR has free ebooks that have been beautifully formatted by some very dedicated MR members.
ePub format and
Sony BBeB / lrf format
Free ebook sites..
feedbooks.com and
manybooks.net
Free and for purchase ebooks ..
smashwords.com and
baen.com Plus Baen (Science Fiction) has a
free library
Plus, here are a couple of book search engines for finding and comparing book prices..
AddAll and
Inkmesh.
Have fun in the forums and ask if you have any questions.
PS Check my signature and click on the links to find more information.