Monte Rio, Guerneville, and Rio NIdo are three small towns along the lower Russian River. The area is famous for summer resorts, so the weather and scenery are obviously beautiful. Redwoods dominate the countryside making for cool shade in the summer, but sometimes dark and damp winter conditions depending on the orientation of the house. There are lots of hills here, so the north side of a hill under the redwoods might not dry out for months. The plus side of that is the amazing ferns, crisp forest smells, and the quiet you can get here.
Real estate prices are among the lowest in the county, so the affordability can be good here as well. There are lots of former summer cabins for sale as the generations that enjoyed the Russian River have passed on and their kids are either relocated or busy with other things. These cabins are often built without much insulation or thought of winter, so they can be more expensive to heat than the more modern buildings that have gone up more recently.
Monte Rio's biggest real estate turmoil these days is related to septic systems and the on again, off again sewer project. I can't take the time to explain it here, but before you purchase a property here you should check with the Sonoma County PRMD to review the septic status. Guerneville is on a public sewer system, so buildings within the district don't have similar problems.
The final useful piece of informaiton you need to have if you are thinking of this area is flooding. Guerneville has 100 year floods about every ten years (joking) and although almost all the housing in the flooded areas has been elevated about the projected flood level, you should still keep that as a consideration when you are looking at properties.
I personally love the Russian River area and the various people that call this home.