I have a “grow room” that I set up in my downstairs mudroom to get my seedlings started in. It has a large southern facing window, an exterior door to the veggie garden, a door to the garage and a door to the basement. I have a large metal rack with 4’ flourescent lights over two shelves (two each). I used a cool bulb and a warm bulb in each light so as to afford a full spectrum of light for my seedlings. We also keep a freezer in this room, so the heat from the lights (which are on a timer set for 14 hours a day) and the heat from the freezer keep the room warm enough for seedlings in winter/spring. I grew lettuces all winter in here. I also have a potting table and a hose right outside the exterior door.
January 2011 – added another metal shelf unit and more lights. Hanging lights from the ceiling over both shelving units to accomodate larger tomato plants as the shelving units are not that easy to adjust for height during the growing season.

Pics
1 – 2011 “expansion”
2 – grow room when first established in 2009