spacecase0.com

seed companies, I have ordered from every one of them and they would never carry a GMO seed,
some are organic, some are conventionally farmed


seed companies from plant breeders, if you can, get seeds here

http://rareseeds.com/ (huge selection, large company)

http://www.adaptiveseeds.com/ (amazing seeds that have a large DNA variation, so saved seeds will give you a good local variety fast)

http://sandmountainherbs.com/

http://www.seedstrust.com

http://www.sandhillpreservation.com/


these also have very good seeds

http://www.southernexposure.com/index.php

http://www.seedsavers.org/

http://www.seedsofchange.com/

http://www.bountifulgardens.org/

http://www.nativeseeds.org/ (wonderful native corn seeds and other natives from america, tested by natives for thousands of years )



large commercial places worth ordering from especially if you need things in bulk

http://www.johnnyseeds.com/

http://www.fedcoseeds.com/


saving your own seeds is critical,
you should only have to buy them one time.
to help with that, here are instructions form a few websites

http://www.seedsave.org/issi/issi_904.html
http://realseeds.co.uk/seedsavinginfo.html
http://www.nativeseeds.org/how_to/seedsave
http://survivingthemiddleclasscrash.wordpress.com/2009/03/23/how-to-harvest-process-and-store-vegetable-seeds/
this one makes you log in, so I figure it is worth skipping...
http://www.savingourseed.org/

storing the seeds correct makes them last longer,
here is a good overview
http://johnosbloggo.blogspot.com/2008/01/personal-seed-bank.html

for long term like a seed bank, here is the best info you will ever find,
but it is doubtful that you will need it, that is unless you are like me.
http://www.seedcontainers.net/a_guide_to_long-term_seed_preservation.html