I prefer Whitetail and Liberty over Roundtop, but all three are fine for beginners and roughly about the same distance (Roundtop is the farthest.). They are owned by the same company and so have very similar pricing.
This is Whitetail's guide for beginners.
http://skiwhitetail.com/first-timers-guide
Skiing will be much more fun if you have the right gear, to minimize the cold and wet. You will need snow pants, snow jacket, waterproof warm gloves, and a hat/helmet.
If you are brand new, I might put your kids in a camp so that the instructors have the job of getting them all geared up and onto a bunny slope for the first time. Honestly, even if they don't learn that much in those crowded group kid classes, it'll be really hard for you to help them if you're a beginner too.
The first time is the hardest but it gets exponentially way more easy and fun from there on out. Have fun and good luck!