I know it's still really early in the year, but some plants recommend seeding 4 to 8 weeks before the growing season! By starting your own seeds instead of buying plants, you know that they've been grown organically and it cuts down on packaging. We started some of ours last weekend in an egg crate and some recycled pots. Here are some tips on starting your own.
Know when to plant - timing is everything and to do so you must know the frost-free date in spring for your particular area. Here's an article from Organic Gardening to help you determine when to plant, and when to start your seeds.
We use egg cartons and recycled pots from other growing seasons. There are also kits available, but those you have to buy new. Non-plantable yogurt containers, plastic lids and berry containers work just as well (but you can't plant it in the ground with the seed) - just make sure to punch holes in the bottom for proper drainage.
Some guides will recommend specialized mixtures of perlite, vermiculite and peat moss, topped with other types of covering mediums. We've had good luck with straight seed starting mix or even potting soil for something simple.
Keep it Warm and Moist:
Finally, keep your seeds well watered and someplace warm with a bit of light. Near a heater vent is a great place to start, or cover with recycled plastic wrap if your house is especially dry.
See Organic Gardening for more tips and a more detailed how-to.