Here are a couple of useful links that I've found about Voc Rehab that will be beneficial to anyone either entering the program or already enrolled:
The first link debunks some myths about Voc Rehab:
http://www.military.com/opinion/0,15202,210234,00.html
The second link provides you with items that Voc Rehab will pay for as long as it benefits your education:
http://www.disabledveterans.org/2012/01/19/va-buys-disabled-veterans-ipads-and-more/
From what I gather, pretty much anything that you can prove that would benefit you educationally could be authorized for purchase by the VA.