First step for this project - scrub everything down. We're forgoing most of the the walls as those are getting painted (kilz primer first), but the baseboards, windows, and door frames are getting a good wash. Oxy-clean seems to work the best (powder into bucket with water - we went for a very concentrated solution - sponges with scrubbing side). We're delighted to find that what at first looked like damage is mostly filth.
For the past few years the house has been a rental and housed several young motorcycle riding and backyard fire having guys (evidenced by abandoned motorcycle hull in rear parking space and somewhat charred tree). Seem like a jolly bunch, no major damage to the house (that didn't come from a mediocre roof situation); some odd painting decisions though (read: red walls and black trim).
Thankfully the house has a surprising lack of pests - the worst creepy crawly inside appears to be the silverfish scurrying through the bathroom. The front porch and backyard are another story. The previous tenants' outdoor cat appears to have left a prolific flea population behind as a legacy. Our solution - the most effective non-toxic option I've found - is to diatomaceous earth* the entire property (wear a basic particulate mask and sprinkle all over, then broom around throughly to get into all the cracks and sweep up). Inside and outside of the house. You can find a small-ish bag at most mega hardware/home improvement stores in the pesticide & lawn care area, or a super sized bag at agricultural stores.
*In addition to fleas, diatomaceous earth is wonderful for cockroaches (mix with flour and sprinkle piles in corners, they will consume and dry up from the inside). Also great for ants and other insect pests - for pets and humans it's only harmful as an airborne crystalline silica at high levels over a long period of time (hence, wear masks and use properly).