In reply to germaica:
Have you looked into the options for getting a guide for the day? Or going on a weekend winter skills course?
The most prudent advice would be 'don't go unless you know how to handle an ice axe and crampons'. Possibly that's overly cautious advice, there's plenty of time between now and the end of January to read up on ice axe and crampon use for winter walking. There's not a lot to it but knowing how to arrest is essential (as is having practised it on a small slope with a short run out beforehand). Gain some basic understanding of avalanches and the conditions that lead to them.
This is an excellent book for the skills you'll need. A day out or two with an instructor would be even better!
http://www.amazon.co.uk/Winter-Skills-Essential-Climbing-Techniques/dp/0954...
Winter hillwalking and climbing is entirely conditions dependent, there's a big difference between fresh powder, wet slush and hard frozen ice. Keep an eye on the weather forecasts, conditions reports etc. Plan for the worst and hope for the best. You should be able to navigate with map and compass, but hopefully you won't need to use them. Bear in mind conditions can change very quickly and can be very localised, and forecasts aren't always correct. Main paths do get very icy from the passage of many boots compressing the snow.
The easiest route would be the Llanberis path. However, several people died there several years ago after snow on the path turned into sheet ice. On a clear day in winter, you may well get hundreds of people on the summit without any winter gear at all oblivious to the risks they're taking!
http://www.ukclimbing.com/articles/page.php?id=1653
Good to see that you're asking questions, and also that you're already thinking of forecasts and getting out early. I hope it all comes together for you and you have a great day out (and many more in future
)!