Right now my employer, the largest college in the state is heading towards using Mobi tablets from eInstruction. http://www.einstruction.com/products/interactive_teaching/mobi/index.html Very much like a wireless Wacom tablet, the only thing you need is a computer with a USB port for its RF adapter and a way to show the video out of the computer. The software that comes with the Mobi has all that is needed for a electronic whiteboard,annotate power points, pdfs, etc. We are buying them at the educational price of $400. And as mentioned in the replies above most classes now have a ceiling mounted projector and computer in each classroom. Just install the software and you can take the Mobi from room to room. It also charges over USB.

There are hundreds of online resources by professional companies that are designed to help students pass certifications like A+,Net+. Along with many if not all Microsoft certifications as well. Preplogic has many of these in PDF format, even if you bypass the free links that sydbarrett74 (74307) found. The Preplogic files are vetted by editors and are very up to date. Other sources you might check for online documents are Comptia and Microsoft themselves. Recently I used a PDF study guide downloaded from Comptia to pass the remote service technician certification. Also working with a PDF or other electronic files have one huge advantage over printed materials. If a student looses their copy, all you have to do is print another. It also allows you to always have enough for your students no matter how many or few you might have. Check some of the sites that offer sample questions from the certification tests or even buy a Exam cram book and use the questions as homework. This will give your students up to date questions. And also give them plenty of opportunities to see questions that might be on the tests themselves.