Aside from being an affordable winter sport (My skis, boots and poles rented for $12 @ REI and a cross country ski pass at Schweitzer was $14.) this is a GREAT WORKOUT! You can burn about 600-700 calories an hour cross country skiing.
We had a brief lesson on XC skiing and that helped me get familiar with the equipment and learn the proper form so I could glide rather than just fall over. What I liked about the XC trail was the two "tracks" your skis fit into. This helped me stay balanced and not topple over so much. I guess the XC trails @ ski resorts are groomed with these two tracks which is really nifty!
Back in the 90's I bought one of those Nordic track ski machines and having that experience was very helpful. Actually, the Nordic ski machine does an accurate job of simulating XC skiing. If you have ever been on a Nordic track, you know it takes a bit of coordination.
It's important to dress in layers when XC skiing because you heat up pretty quickly. Dress lightly. You'll be shivering @ first but that you'll be overheating after 20 minutes.
Give XC skiing a try. Take your time. Go on a sunny winter day. Pack a lunch and bring plenty of water. That's my plan for next time and I can't wait to go again.