Beginner photography

I fiddle.  And photo edit with Picassa.  And learn by doing.  But I get frustrated trying to figure out why it is that one picture looks awesome and another looks horrible (grainy, dimly lit...).

If I am going to invest in a better camera, I want to know how to use it!

I found this site.  The first site I landed on from my Google search.  It's great for me - a beginner-fiddler.  Now I know what to invest in, how lighting works...etc.  It's a whole beginner course in the simplest terms.  Perfect.