You will get 25 bulbs (more or less, they're in clumps) from my onion plants.  The whole plant is edible.   They are top setting and reseed themselves.   They make nice additions to soups or salads and go well in any dish you want onion flavor for.  

Plop them in the ground cover them with dirt.  They like full sun and have thus far survived subpar soil (am I joking?)  and late summer neglect for several seasons now.  They absolutely will spread so give them room or prepare to be merciless.