I'd agree with the 'do some of the popular munros'. Some easy winter munros are probably ones like Ben Narnain via the col with The Cobbler, Ben Ime, Ben Lomond, Cairn Gorm by way of Fiaciall Coire Cas/Windy ridge, Ben Chonzie... Easy being a relative term of less hard than some others but you still need to keep an eye on the snow pack, where exactly you are walking (over a snow bridge/lochan/only just frozen bog...), how long you are taking/etc/etc, how much daylight left.
As for equipment (hope this doesn't come across as teaching grandmother to suck eggs!): head torch for each member of your party tested with fresh batteries - with someone carrying a complete spare - only needs to be something like a Petzl e-lite, extra insulation layer - belay style jacket that can slipped on over whatever other layers you have on at stops, gloves, more gloves, more really warm gloves..., balaclava or arctic buff/warm hat that wont blow away in a gale. A bothy bag can be good for getting the group, or at least some of the group out of the wind, and if you are out on your own you should have an emergency bivvy bag anyway. Even if you have a waterproof Harvey map put it in an Ortileib map case and attach the string to your jacket, or pack, so you don't loose it if you let go. When I bought a new compass, I put the old still servicable one in my first aid kit. Crampons that fit your boots, and an ice axe along with the knowledge of how to use it/them.
Winter is an awesome time to be in the mountains. Pick some stable, nice weather just get out there
