In reply to Robert777:
I am definitely biased, as I offer winter skills courses, but I would say you'll gain an awful lot from doing a course that you'll never pick up by watching youtube videos. Going out into the winter hills is very different from summer walking. Buying suitable axe and crampons is the start, then learning how to use you boot as a tool, and how to cut steps with the axe, then how to walk in crampons whilst not stabbing either yourself or those around you, and learning how not to trip over your own crampons. Then there's route choice, taking into account the weather, wind direction, snow conditions, freezing level, and avalanche dangers. Then there's winter navigation, when all paths are covered by snow, and you can't see most features such as cairns, walls, fences, ridges, crags, tarns, and all you have to navigate by is contour interpretation, distance measuring and a compass bearing. And that's in good visibility. In bad visibility you won't be able to make out contour features either, so being able to walk accurately on a bearing for a given distance is absolutely essential.
As I say, I am biased, and you will be able to learn some of this on your own, but personally I would get professional advice.
Hope that helps.