Seed saving and seed banks

A big reason for my interest in commencing permaculture studies is to do with food security. I want to ensure self sufficiency through growing my own produce, collecting the seeds, and replanting the next season to develop robust crops, that are suited to this climate and environment. It makes such sense to create community seed banks where seeds can be traded and local food security can be maintained.
So much of what we can buy from stores is genetically modified.. seeds and produce. 
I have a few store bought herbs growing in my garden right now that i have been contemplating pulling out.. to remove GM plants or any that i'm uncertain about so that my efforts towards getting heirloom seeds won't be in vain.
So much to learn on this topic and i feel a new passion arising :)
So much to share, as well. this is vitally important knowledge to pass down to my kids.. cos who knows what kind of food will be around when they're grown up trying to source healthy food for themselves and their families.