I am a young parent and a college student attending SIU. To be honest, the only reason I am living in this city is because of SIU - it is the only 4 year school in IL that has my program.
Carbondale is strictly a college town. It is directly towards college students. So for the college life style, this city is great. Most homes for rent and job openings are aimed at students only.
For families, this is a down right awful place to live. There are hardly any job openings wiling to hire non-students. There are hardly any family-friendly activities.
There is also a lot of crime in this area. And the schools aren't great.
If you plan of having a family, then you'll definitely want to move away.