Everybody has had good advice, definitely get well hydrated even before you get here it does make a big difference. I would take it pretty easy on the beers the first night too.
As far as the Breck goes you should ride the imperial chair to the top and traverse over to Whales tail and even farther (go all the way to the boundary line and ski that all the way down). The south side of Peak 10 is steep and usually holds some good snow, but it has a long flat runout. The windows are great tree skiing and if you're motivated you can hike farther back for some of the goods.
Everybody has been saying go to A-Basin and it is worth the trip to experience the mtn, but they just have not been getting the snow that some of the resorts farther west have. If I were you I would not miss Vail. For someone who has never skied out west the bowl skiing at Vail should be experienced.
Lots of good places to grab drinks and food in town here, as previously mentioned the Breckenridge Brewery is good (half price apps for happy hour). Another good place for happy hour is the mexican place Mi Casa, cheap pitchers and wings. Fatty's is a great pizza shop and right across the street is Angel's Hollow; a cool little place with some character.
As far as demoing goes I don't know if you are already lined up somewhere but if not you should go to AMR (right by city market) the owner Dave is a great guy, very knowledgeable and has a pretty good selection. Feel free to shoot me a PM if you want to meet up for a beer or possibly a day at the mtn.