I mainly learn now by looking up things when I have a need and then hoping to still remember it 3 months from now when I need it again. The material covered in your tutorial is kind of the daily bread and butter stuff that I use and am comfortable with, but I know just enough to understand that there is this whole other level to SQL querying - even without really dealing with Database Administration and index tuning.

I guess I will just keep learning as the need becomes apparent. Anyway thanks for making your resource available.