Have a look at our wiki.
(There's a link at the very top left of this page.)
There's a page on E-book stores:
https://wiki.mobileread.com/wiki/E-book_stores
And on E-book lending libraries:
https://wiki.mobileread.com/wiki/EBook_Lending_Libraries
Also on sources of free books:
https://wiki.mobileread.com/wiki/Free_eBooks
Also, we have a book upload section of our own: click on "Ebooks" on the blue bar toward the top of this page. With a 505, you will want books in LRF or EPub format.
About the newspapers: if you download Calibre, you can use it to synch papers to your reader. Just check out the Calibre section of the forum. It also converts books and is a library management tool.