The best you can do is keep them as dry and cool as possible. Some people even refrigerate or freeze them. Also keep them away from light

Jared,
Only a a very few seeds go bad right away. Those are the mostly spring ephemeral woodland plant seeds. Most seeds last a few years. Some last a very long time.
Keeping seeds in a cool dry spot as stated above will keep seeds in their best condition.
Remy

Not all seeds can or should be frozen. Use care and check first before seeing if it is OK to freeze the variety.

Sue