cryrose has some very valid points, online people tends to be a bit like 'speed dating' because thee are so many other prospects... what I actually suggest is getting out to a local munch and talking to people there.

After the initial 'omg I don't know anyone' passes I'm sure there are plenty of people there who are willing to mentor and what's even better is that you can ask for 'reviews' of those same 'mentors' in person from other people who have been 'mentored' or 'play partners' etc.