I don't have a Kindle, but you might and so might your students. SENDtoREADER is a bookmarklet that you can install on mostly all the main browsers out there: Firefox, Safari, Opera, Chrome, Internet Explorer. You must register for an account to use the service, so I suggest that you do that. When you use the bookmarklet it will automatically remove all unnecessary content including: ads, polls and banners but leaves the main content intact.
SENDtoREADER "retains all images that are part of the text you send to your Kindle reader so you don’t miss out on seeing them when you have the time to read the material you have saved. If you have long articles, items you don’t have time to read, or you don’t want to strain your eyes by reading from the computer screen, you can send articles to your Kindle for comfortable, stress-free reading from its legendary e-inc display at your leisure. You can keep track of every single item you have sent to your Kindle from any other source and can always resend items if necessary. This means you don't have to keep the articles on your Kindle once you have finished with them. This also eliminates the concern that you may have deleted something important."
As textbooks become more mobile, software and applications such as SENDtoREADER will become a valuable addition to reading various sources.