My wife and I will be travelling to southern Germany in June. Would like to rent a room in a residence in the Odenwald area, possibly Eisenbach---love to hike. How do I find a site to research this and make arrangements?
Look for pensions. That's essentially what you are describing. Some pensions are a little more like hotels but most are just homes that rent out rooms. In most cases it's like staying in a guest room here, including a bathroom in the hallway rather than in your room. In Germany, pensions are a popular choice. I've stayed in pensions in many parts of Germany, the cleanliness/quality standard is consistently high.
Look up phrases like "Zimmer Frei", "Apartmentvermietung", "Gast Zimmer", "Gasthaus", "Pension", ect. BTW, the Odenwald is a hiker's paradise, but I'm not aware of a town called "Eisenbach" located there. Did you mean "Erbach" (which would be a good choice) or Eberbach? "Eisenach" is another great town, but that's located at the foot of the Thüringerwald, nowhere near the Odenwald.