Lots of web sites and books provide such information, but you shouldn't overlook information on the back of seed packages. There the plant is described and directions are given as to how to sow the seeds (when, how deep in the soil, how far apart), and more.
Someplace on the package the seeds' expiration date should be given, usually stamped on. Remember that seeds are living things, and they contain only a small amount of food to sustain them. Old seeds simply starve and die. Refrigerated seeds may last longer than specified. Still, you'll always have better luck with "this year's seeds." Below is a close-up of the side of the seed package summing up the plant's needs.