SNAP! It's my birthday Tuesday, and I too was allowed to buy a 580. Got to use it at a wedding yesterday, just about to download the pics. I loved it!
I tended to use ETTL for most things and tweek the FEC, it did the job beautifully for me as a noob. The thing I need to master is the cameras exposure and the use of P mode or Av to get backlit scenes right.