I grew up in Cottonwood and loved it there. Anderson is a hole and a crappy place to move too. Full of crack heads in my opinion. Cottonwood is pretty well-to-do and has plenty of homes with acreage. There is also a community called "Lake California" that is pretty neat. I was thinking about moving there(if I can ever afford to leave Sacramento!!!).
Lake California - Home
There is a realtor there that I really like. He and his daughter run Vintage Realty there in Lake California. Honest people are hard to find, but he "seems" honest to me. He could probably help you find places around Cottonwood too. Send him an email, he answers his emails almost daily. You can get his contact info on their website:
Vintage Team - Home Listings
To answer your other questions:
Air Quality - It can get bad during the summer months when the temperatures average 100+ every day. It is better the farther away you live from the freeway(I-5). They have some good acreage properties far down a raod named Gas Point.
Schools - I know Evergreen Elementary(have to live out Bowman Road area or Lake California) rates a 96 statewide and is excellent. I went to East Cottonwood Elementary and West Cottonwood Middle Schools and I thought they were good schools at the time. They also just built a new school called North Cottonwood for 7-8 grades. I graduated from West Valley High School...was rated very high when I went there in the late 90's, but it appears to have dropped just a bit. It rates in the mid 80's now statewide...not bad, but not in the 90's either.
There is also a landfill between Cottonwood and Anderson that can stink up the joint, so be mindful of that as well. Cottonwood has a great parade that runs through the historic part of town. All in all, I would rate Cottonwood as one of the most desirable places to live....for me anyway. I fully intend to save enough cash to move back there and raise my family before my oldest turns 10(she's 8 now).