Soon I'll be starting seeds for a few crops that will go in a cold frame, probably early April here in Colorado, Zone 5b. I actually already have one cold frame planted. I started the process too late for fall-early winter harvesting, but I did put in a few spinach & lettuce plants in November that will hopefully survive enough to begin growing as it warms up in spring. It's an experiment--we'll see whether it's worth trying again.
I'm using the garden planner offered at GrowVeg.com, which has been fun to play around with, and much improved after I tried it when it first came out. Here is a snap of my 2010 garden. 2011 is on the way, but changes are still being made!