HTC Aria can read Android eBooks! It's a great way to take your entire library with you wherever you go.
You can read ebooks on Android with the Aldiko ebook app. "Aldiko Book Reader" is great for ebooks because it allows you to read your own files as well as ebooks that you buy online. It is also compatible with Adobe DRM ebooks.
The best Android ebooks are those in the PDF and ePub formats.
Both of these ebook formats will work on the HTC 7 Mozart with the free Aldiko app, which you can get in the Android Market.