I believe that music(for pleasure) is best explored almost serendipitously, rather than by following a set program. I have found many great composers through: online reviews; eMusic's Magazine section (which has been extremely helpful); chance hearings; and my first trip to a professional concert 2 weeks ago, to see the Bournemouth Symphony Orchestra (absolutely amazing
).
Start with whatever initially captures your interest, then go to Amazon for recommendations of similar items, etc. Join up at Naxos, and read their reviews. Read quality forums, such as this one
Finally, listen to Classical music radio stations, there is bound to be something that suites your fancy.