I'd suggest an Android tablet. Go to a computer store, try out the different ones and choose the one that seems best for your purposes and budget. All of them will support a multitude of free reader software, making the words as large as you want, backlighting, etc. There are different models that have different size screens, different features, and different prices. Most of them are a lot cheaper than iPad and do all the same things and more than an iPad.
You can download free reader software to get free content or to purchase content.
On my Toshiba Thrive android tablet I use Nook, Kindle, and Aldiko readers, all of which were free downloads. I have read a lot of books and magazines on these and have never paid a dime for content, although there is plenty of paid content available. It's also good to have multiple readers if you are purchasing content -- often the same content will be a lot cheaper on one reader's store than on the other ones.
Many libraries have books available for download for free, but often they do not support Kindle or Nook data formats. This is another reason why it is good to have other reader software available.
Good luck!
Last edited by QKO; 06-30-2012 at 02:12 PM.