We usually have pretty good results with our seed starting, so I thought I'd share our methods. We have a tiny extra bedroom in our house that becomes our plant nursery in the spring. We have a four foot long wire shelving unit that we clear off and set up with lights. We put rope lights on the shelf itself (which generates just enough heat to keep the soil nice and toasty), and have three four-foot hanging fluorescent light fixtures, which have simple grow bulbs that we picked up at Home Depot or Lowe's in them. We use organic seed starting mix; I personally like the Burpee mix in the white bag because it holds water pretty well and is easy to work with.
We bought a hundred or so starter trays from Greenhouse Megastore a couple years ago; we are using those for our starter plants. Todd is very meticulous with his seed starting-- he likes to make sure that if the package says 1/4 inch depth, he's putting them in at around a 1/4 inch; I like to throw seeds on top and poke them into the dirt with a chopstick and cover them up very unscientifically. Both methods seem to work fine, and no significant difference is sprouting has occurred. Also, I water from the top and Todd waters from the bottom-- for this stage of plant life it doesn't seems to make one spit of difference. Once the plants sprout, we move them to a sunny window and make room for more. We can fit four trays per shelf, and I think the most we have ever used at once were three shelves (so twelve starter trays all together). At 18-128 plants per tray, that's a hell of a lot of plants. :)
If you're not sure when to start seeds, there are of course tons of great books, charts and websites. This year, we're using the Farmer's Almanac dates; you can find their website here. We have already started onions, peppers, tomatoes, lettuce, cabbage, Brussels sprouts, broccoli, celery, and some herbs. We'll be starting more seeds later today after we get back from our maple syrup adventure. :)