Not being a teen or actively raising one I haven't spent a ton of time on the site myself. I can say, though, that every sex blogger who I have ever heard respond to a question about good sexuality resources for teens has spoken immediately of Scarleteen. The team over there has worked to answer questions thoughtfully, to include all types of people, and to make it easy to ask the hard questions.
I do think it's important that kids feel comfortable asking anything of their parents. However, I don't think all kids will feel that comfort regardless of how open and welcoming their parents are on any topic. I also think that learning how to find answers on one's own, from reliable sources, is a valuable skill to have. Scarleteen is, from what I've seen and heard, the very model of a reliable source. I encourage we children of all ages to support and utilize the site to its fullest.
Happy Back to School, wherever that may find you!