The Nokia 770 or the newer N800 are good choices for reading e-books. Both run FBReader, which you can try out on a Windows or Linux Desktop.
The FBReader
web site, includes
screenshots of FBReader on the Nokia 770 which also serves as a mini-tutorial. Note that when you click on the images you get full (800x480) size versions. These will most likely appear bigger on your desktop screen than on the device, because the 770 has about 220 pixels per inch.