I'm with Zen on this Spins.

I think you start looking at bikes now. They can be set up indoors on trainers in the LBS's for you so you can "get a feel" for whether the frame is the right size, or the handlebars are narrow/wide enough

Then, come good weather and ability to "test-drive" you will have narrowed down your choices so you have just your favourites to choose from...




*Rave puts on her horns and red cape*
...then, decide your favourite three and buy.... ALL THREE!!!!
Bwahahahahahahaha...