If you're just trying to expose your kids to skiing, there are several easy ski spots not so far outside of NYC, which make for an easy half day trip. We went to Mt. Peter, which was about 1.5 hours from Brooklyn, which means it's completely feasible to leave by 8, and even make it back for a late lunch. (That is, if you don't make stops along the way, like we always do.) And if you do stay there through lunch, they do serve hot dogs and hamburgers--get them from the outside grill...and there is a full bar inside.
Here are a couple of other places--all of them great for beginners.
Campgaw Mountain--this is just 20 miles from the GW Bridge, making it the closest skiing to NYC.
Mountain Creek in NJ
Tuxedo Ridge, NY