Use Craigslist. Grand Rapids, MI. Click on the apts/housing. In the search field at the top, type in Greenville.
Also check out their newspaper which can be found online. The Daily News - Greenville, Belding & Montcalm County, MI
As for information...... what are you looking for? It's become quite depressed economically with the loss of their largest manufacturing plant (which in turn hurt several smaller businesses that supported it). It's saving grace is it's proximity to Grand Rapids where a lot of people commute to work.
Greenville is my hometown but we saw the writing on the wall and got out the summer of 2005. We timed it right because the house we used to own is now valued at 50% of what we paid for it.
We have several friends and family members in the area still and go up there throughout the year to visit.
Feel free to ask any specific questions