warning, I ran on a bit long here....
put someone else in charge of your bank account
Seriously, though - before you take a single step, get a good idea of what you really plan to acomplish. Then, think about what it's going to take to pull it off. You've already said "small, home-based" but that could mean wildly different things to different people.... Are you thinking of scope in regard to the number of "morphs" you'll be able to breed? or the number of breeders you'll keep on-hand?
I guess the smallest you can get, while seriously wanting to breed would be to have at a minimum 2.2 cornsnakes (2 males, and 2 females) If you want to keep it this small, but still have some "variety" in your offspring you still can; you'd want to get (for example) a pair of males that have caramel, amel, & motley genes (i.e. butter motleys) and a pair of females that were HET for those traits, or perhaps a caramel female het for amel and motley. In either case you'd get a wide variety of hatchlings. For example butter motley X het for butter motley would give you:
normals
motleys
caramels
caramel motleys
amels
amel motleys
butters
butter motleys
So having to be "small" doesn't mean you have to have boring offspring! With 8 types of offspring you might even be able to justify starting with 3.3 pair for real security that each season you'd have SOME good offspring!
Of course this is a narrow path, and all you can really do with selective breeding is hold-back the ones that appeal the most to you and refine the patterns and colors in your line over time. This MAY be thouroughly engaging for some, but others might prefer more "cutting edge" breeding programs, like integrating motley (or stripe) or even aztec or zigzaag into other morph lines.
So - what does "small" mean to you? Do you have a notion of how many snakes might be too many? What interests you most about breeding? What will it take to get you from here to there? Is it really conceivable? Is there a way you can start with 3 to 6 snakes to "get the gist" of it all? If you get 100, or 500 hatchlings in the course of a month, will you be able to manage them? Will you be able to handle the effort involved in finding buyers for the ones you don't want to holdback?
There's a 1001 questions to ask yourself - maybe we should work-up a FAQ for people that ask this question!
^Curtis