One of the online resources I track as part of my flight training is Private Pilot Study, which uses Google+ hangouts to lead video conference briefings on different elements of pilotage.
Tonight the topic is airspace, and it’s being led by Keith Smith, founder of PilotEdge and one of my personal web-aviation heroes. Time is 7 PM Mountain time US. If my schedule permits I plan to attend.
As for Private Pilot Study, it’s an excellent resource with twice-weekly instructor-led sessions on all matters of private pilot knowledge. If you can’t participate in the hangout you can watch real-time, and if you can’t watch due to your schedule, you can view later via the archives. Check it out.