I love cold weather; fall is my favorite season, and the idea of winter coming just behind only makes it better. But I still hate the loss of the beautiful view out of my kitchen window; after the red and orange and gold of fall, I'm left with brown. The huge expanse of trees across the road is just a huge expanse of brown, and the grass in my front yard fades to a dingy yellow. Even the pine trees get a little puny looking.
Hence the windowsill gardening; I need a little green in my life. It's good for cleaning the air inside the home, which is important in winter when we're all inside much more than any other season, recirculating the same air. Having some small, growing, green thing around somehow just makes the whole atmosphere better. The coldest days of winter, when all we want to do is sit by the fire, feel less confining and more cozy when I can still glance up and see a bright green leaf, a cheery plant, maybe even a bloom or two.
To start your own windowsill garden, find a nice sunny window. A window facing the east will get fabulous morning sun, which is often adequate even for full-sun plants (they'll grow more slowly, but they'll still grow). A southern-facing window will get the most sun. A window facing the west will get afternoon sun which can often be enough for good plant growth. Watch out for northern-facing windows, as those get little natural light and also stay much cooler. If your only option is a northern-facing windowsill, plan to supplement with a bright light or lamp on nearby for most of the day.
Once you've figured out where you want to start your little indoor garden, you'll know how much space you have. For indoor gardening, it's almost always very little space to work with, so we're going to stick with smaller plants. Culinary herbs can work great, because even though many of them grow quite large, if you're continually clipping off leaves to use in your cooking, you'll keep that size in check. You have other options, too: you can force bulbs (hyacinth, narcissus, daffodil, tulip) which will be somewhat tall but not at all broad. Or you can simply go for a smaller plant: Chinese Evergreen, Bird's Nest Fern, a small cactus, or any diminutive flowering plant such as African violets, pansies, geranium, begonia, or corydalis.
Follow the particular planting instructions that come with your plant of choice; be sure when you plant that your container has holes for drainage and a good layer of pebbles in the bottom. Water regularly, keep the plants in the light, and run a humidifier if the room is very dry. (If you don't have a humidifier, setting a bowl of water out at night, next to the plant, can help.) You'll soon have your own bit of green inside to make the winter days a little more colorful.