Here are some free courses you might like to try out from the Open University:

http://www.open.edu/openlearn/science-maths-technology/free-courses

Click on Astronomy in the left hand filter bar.

There are courses on:

  • The Sun
  • Moons of our Solar System
  • In the night sky: Orion
  • Galaxies, stars and planets
  • The Moon
  • Active Galaxies
  • Jupiter and its moons
  • And many more… all free…