http://my.americorps.gov is the official online paperwork and form submittal tool from Americorps.
Setting up an account is simple. Just go to http://my.americorps.gov and click on "Register to create a new Member/Alum account" at the bottom of the page. Drop your SS numbers and a little info and they'll send you an email that will link you back to your account. Set your password from that link and you should be alright. Once you log in click on "My in-service benefits", "My Education Award" or "My Service Letter" on the left sidebar to start accessing your info and forms. As of now the "My Living Allowance" and "My Tax Statements" information is not relevant for CTC VISTA's since we handle this in-house.