Sherri,
I've done a little more research and have decided that the virtual author's assistant certification is a few steps from being a scam. This is just my opinion, but it doesn't pop up much in web searches and no authors have heard of it....which means it doesn't carry any weight with them.
I think it's probably best to just offer services that would benefit authors (proofreading, etc) along with other VA services.
One of the best ways to reach out to authors (judging from my experience) is to start a book review site or blog. That's how I got the ball rolling. The process can be fast or slow, depending on what you review. Most reviewers won't touch e-books so including that media form got a lot of attention for me. Also, the genre you review matters. I like paranormal fantasy/urban fiction so that's what I review, but that genre is saturated so lots of people going for the pieces of that pie.
One place authors hang out is
Absolute Write so you might want to check that place out.