Storing seed is easy to keep in an air tight container out of direct sunlight.  They may not look like it, but seeds are very much alive for years to come. However they don’t remain so forever. How long seeds remain viable depends on the type of seed and how well it is stored. To store them for the longest time, be certain they are completely dry, to the point of being brittle, before you pack them away. 

Here are some average years of viability for well stored vegetable seeds. To be fully certain of your own seeds, you can also do Watters easy viability test on your seed.

Seed Storage Guidelines