On the e-ink screen you can open both ePub and PDF books and annotate them.
On the LCD screen you need a reader app for each format you want to read. A good all round reader is CoolReader
http://sourceforge.net/projects/cren...s/CoolReader3/ that will open ePub, PDF and HTML.
You can also convert between different formats using Calibre on your PC
http://calibre.kovidgoyal.net/ , it will also download your books direct to the edge.