I lived in Cdale for roughly seven years, and can recommend a few places.
As far as housing goes, go out of your way to avoid Home Rentals (the company). They are pretty well the most notorious slum lords of Carbondale, and in all my years in Cdale, I have yet to hear a good story from anyone who rented through them.
A rented a 2 bedroom house for 3 years though Compton Rentals; Dave Compton was a really stand up guy, and if we ever had any problems with the house (which we rarely did), he was usually able to come out same day and fix it. That was about 700 a month, with utilities being pretty cheap- propane gas though, so if you ran your heat a lot in the winter, you'd end up paying for it.
If you are looking for a quiet area, maybe try S Oakland Ave. That is really close to the campus, particularly the law school. Many professors live in that area, but you can find some house rentals that are reasonably priced and nice and quiet. Also check out S Wall Street, south of East Grand Ave. Avoid the two apartment buildings (The Quads), but the houses on that road at cheap and moderately secluded, and still right across from campus.
Avoid Cherry St and College St, generally. Those are heavy student housing areas, and tend towards the party crowd.
Maybe check out Pleasant Hill rd, you might be able to find something there, but that is pushing the limits on carless commute.
House prices range from about 650 to 1200, depending on the size of the house. Most two bedroom places are around 700. If you look around, you can find bigger for a decent price. I lived in a 4 bedroom place that ended up being 1000 total, so with three other people, that made for cheap living.
Hope this helps!