A look into classical

Lots of classical variety on Internet Radio.

All you need for a great variety of Internet Radio with excellent sound is a Network Player like Roku Soundbridge (<$200) or Squeezebox, a high speed internet connection, and a system.

If you are so inclined to spend the money for a subscription, Grammaphone magazine is a great resource. Each issue has a cd of a collection of recently released pieces. If you aren't sure you want a year's subscription go to Barnes and Noble and get the recent issue to familiarize yourself with it.

Here are reviews of Gramophone's last three recordings of the month http://puresuperaudio.blogspot.com/2009/02/gramophone-recording-of-month.html

for more reviews I suggest visiting http://sa-cd.net/reviews/0/5

If you like that Mozart disc, then I can recommend you try:
1. Mozart Symphony #40, or better yet pick up from the library this double-cd set "Mozart - Symphonies 35-41. Herbert von Karajan, Berliner Philharmoniker"
2. Mozart Clarinet Concerto - Sabline Meyer, Claudio Abbado.
3. Beethoven Piano Concerto 1&2 and Piano Concerto 3&4 with Yefim Bronfman
4. Mendelssohn - violin concerto(pick this one up with Jascha Heifetz or Hilary Hahn as soloists)
5. Bach Violin Concertos. Readily available should be the ones with Hilary Hahn.
6. Tchaikovsky Piano Concerto #1
7. Saint-Saens Piano Concerto #2 - if you can find this with Bella Davidovich and Neeme Jarvi conducting, this is the one to get.
8. Paganini, Spohr violin concertos - Hilary Hahn

This should be sufficient enough to start and for you to see what you like. You have to start with something light and then make a natural progress into more modern classical music.

Lot of good suggestions above. If you favor one or more instruments, you might want to seek out compilation that offer different works by different composers based on that particular instrument that appeals to you. Soon you will have favorite musicians and composers. It's a big ocean out there, don't be afraid to just jump in!