Look at
http://calibre-ebook.com/user_manual...pported-in-app first.
You're device will most likely supports PalmDoc PDB files which calibre can produce. You can use the connect to folder option to get books onto the device for the time being.
Do note that PalmDoc PDB files do not support any styling or navigation. So you will basically be reading one long text file. It might not be very handy for reading news.