Many library resources are available as e-books. L&IT has published a document that provides some good information regarding what type of e-readers are recommended - that document is available here:
https://researchbysubject.bucknell.edu/ebooks
The most important thing to know about our ebooks and ereaders is that many of our books download as EPUB files, which aren't compatible with Kindle. Many people use an iPad with the Bluefire Reader app but there are other apps available for iPads or for Android devices. Some of our vendors (like ProQuest) have their own apps, which might have more options for annotating, syncing, etc. Our JSTOR books are DRM-free PDFs, so you can read them on pretty much any device.