Mason, i guess the first place to start is what utilities are in the basement, do you have to deal with furnaces/water heaters? How many total square feet are available? What about plumbing service? Do you have room for seperate baths? What about codes, will they allow for you to transfom your house into a multi-family unit? Do you have seperate egress windows for the seperate units? Meters, how are you planning to handle who pay for utilities? I'm sure theres more, but I guess we can start here.
...oh and to House Repair Talk!