Lemons are a good source of vitamin C. They also work well in recipes and drinks.
They grow indoors with adequate sunlight
They are trade goods...
So, simple instructions on how to grow them from a grocery store lemon seed.
http://www.offthegridnews.com/survival-gardening-2/how-to-grow-a-lemon-tree-from-a-store-bought-lemon/DO NOTE, the need to remove the tough rind on the seed itself (not the lemon rind, you eat that). but the white coat on the small seed itself.
PS: three to six years to first harvest, plan ahead...