Understanding gears & cranksets (Page 2)

You know enough (now) to be dangerous.  My advice is to take your bike into the shop and describe your situation to the mechanic.  Explain which hills you really struggle with and what you want to accomplish.  Be prepared to get on the bike and ride it on a trainer.  The mechanic can quickly spot whether you might benefit from shorter crankarms, look at the front/rear deraileur and almost immediately tell you which options are "easy" and which are "more difficult" and how much gain you'll get with each change.  That way, if you do go ahead with a compact crank, you can get one with the right size crankarms (the first time), which compact crankset you'll need, and you'll know if changing chainrings requires moving the front deraileur (and how easy it will be or what will be the symptoms if you don't). 

If you're not happy with the attitude/service from that mechanic, try a second shop.  The goal of the LBS is to make money from satisfied customers.  My experience has been that the LBS mechanics are more than willing to talk to the customer (me) and help guide me towards acceptable solutions (and this includes being sensitive to costs).  Good service costs more than mail-order parts and do-it-yourself labor, but establishing a good relationship pays off in the long run.