MLP:
I have just started doing this (fulltiming, mainly in California) and bought my Thousand Trails Platinum lifetime membership transfer through an RV campground membership independent broker in Florida, last summer. I have stayed in 8 of the 14 California Thousand Trails preserves since then. Some in Southern California (Wilderness Lakes and Pio Pico) are pretty nice, in the country, but very near all the city amenities. Both of these have two sets of pool/spa facilities. Palm Springs is nice, but crowded, Soledad Canyon is there (near the L.A. basin) but the facilites need a lot of work. Santa Barbara is actully about 30 miles from Santa Barbara on the Eastern Side of some steep hills, no phone or internet. San Benito gives you access to the Monterey Bay peninnsula, but the park is a little remote (15 miles south of Hollister). It also has a pool/spa. Minden is 20 miles North of Sacramento, and was convienent for me in shutting down my Sacramento house. Best sites there are "out back" in the D section that doesn't have sewer hookups (but does have a dump station in that "D" area. Right now I am on a 21 day stay at Russian River along US101 at the northern end of the Sonoma wine country (Francis Ford Coppola's winery is in the neighborhood). No sewer hookups here, either. Being single, and with the Bighorn's big tanks this isn't too much a problem, they have honeywagon service wherever sewer hookups aren't present, and I don't see it too big a deal to unhook the water, electricity and satellite temporarily to pull the Bighorn up to the dump station, if I choose to do so.
My yearly membership fees are right at $600. I can go 21 days in a park, park-to-park, 7 days away and back to the same park. I have reservations this summer (I have the rest of my year planned out) at TT's on the Southern Oregon Coast, TT Snowflower (Emigrant Gap along I-80 in the Sierras), and TT Lake of the Springs between Marysville and Grass Valley in the northern sierra foothills. I used the TT membership to get me a 50% discount at a plush Encore park in Mesa, Arizona in March for a couple of weeks of baseball spring training games.
I hope this helps. PM me for any more detailed info you might want.