The process of getting ebooks from the internet is quite easy.
Get your computer hooked up to the internet
Get Firefox and a torrent finding addon. (tbar is one, torrent finder is another) Click tools and then addons.
Get a torrent program and install it. (In windows I use deluge)
Get a program called Calibre and install it.
Type a search term on the torrent finder. (something like scifi ebook or NY Times)
Download the torrent.
Unpack the file.
Start Calibre and load the newly unpacked files into it using the "add books" button to take the new books from the folder they were unpacked in. There are three options on this tab and you need to figure out which one is right.
I have a separate Calibre library for dealing with file format issues before I transfer the new books into my main library
It might be wise to have a directory for the new ebooks so you can check for format before including them in your main library.
Fix the titles and all.... Especially ensure that the authors are actually authors and not titles or some mishmash.
Plug in your ebook reader,
In Calibre you hilight/select the books you want on your reader and click "add to" and put them into the folder that is your ebook reader. (either the reader itself or your SD card) The last step is really a function of your ebook reader and operating system. In linux I simply goto the media folder, find the ebook reader and copy the files. In windows it is more complicated. I like to let calibre do the work. Tis done.