In absolute terms, Becky, a road bike is the way to go. It聮s more aerodynamic than a cross bike, and the drop-style handlebars afford you a greater variety of hand positions so that you聮re more comfortable on long rides.
Giant FCR 2 bike
FCR 2 bikeBut life is relative, not absolute. Road bikes have their disadvantages, especially if you haven聮t ridden one before. In short, they can be dreadfully uncomfortable due to the hunched-over riding position. So you have to take that into consideration.
In a cross bike, I like something such as Marin聮s Lucas Valley (US$800; www.marinbikes.com). It聮s a fast cross bike, with a light aluminum frame and road-style tires. But it聮s also got the slightly upright position you聮re accustomed to on your mountain bike, and a triple chain ring for hill rides. Also, it can take light touring gear, so you can put on fenders and some racks and spend a few nights on the road. Giant聮s FCR2 (US$650; www.giant-bicycle.com) offers a similar package in a bike that聮s sized and fitted for women.
You might also look at a touring-style bike. These have road geometry with a slacker frame for a smoother ride and typically offer a little more upright seating than a true road bike. Trek聮s 520 (US$1,200; www.trekbikes.com) is a classic of this type, with a comfortable aluminum, upright stem so you聮re not crouched over but are still fairly aerodynamic. It has lots of places to attach fenders and racks, and gearing that聮s well-suited for long rides. It聮s an excellent all-around bike.
My advice: Test a few different bikes to see what feels right. Try to persuade the shop to let you have five miles or so on the bike, so you can really get a sense of how it聮s going to feel after more than a few minutes.
Happy riding!
You聮ve got your winter gear, now get outside and use it. makes it easy to find nearby slopes just begging for fresh tracks.