Brita,
I'd recommend Calibre (
http://calibre-ebook.com/). It has everything I need, and will probably work for you, too. calibre is a free and open source e-book library management application developed by users of e-books for users of e-books. It has a cornucopia of features divided into the following main categories:
Library Management
E-book conversion
Syncing to e-book reader devices
Downloading news from the web and converting it into e-book form
Comprehensive e-book viewer
Content server for online access to your book collection
Best of all, it's free. And we LOVE free!