+1 Impressive site. Clean design sets this site apart as a great example in this nascent niche.
One constructive criticism: I would add some more space around the "Search" functionality. This area is a little cluttered at present (too close to the preview image on the right and the high level process text/images below) and my eye I think you would improve conversions by emphasising this section a little more (since performing a search should be the "call to action" for visitors).
I've put a lot of thought into creating a similar site but for mentorships, in particular for the growing population of autodidacts, unsatisfied school students, and in general people unhappy with their education.