This is definitely what I consider a "city person" campground. For the person who doesn't want to be too far from a store, wifi, hot showers, electricity. I took my toddler with friends and we had fun, a large part of it was because it was set up for kids/families. There are several playgrounds on the property.
Here's the catch. You could end up with a terrible campsite or a really great one. By terrible I mean nothing but a little space to fit maybe a two man tent and a small vehicle, and with no shade or privacy, and no running water in site and no bathroom nearby. By great I mean having terrific trees bending cozily over and around spacious somewhat grassy areas with a water spigot nearby, wild shrubbery pruned back to border the site for privacy and additional shade, space for large tents or perhaps three or four two-man tents. So the range of what you can end up with as a campsite varies greatly. Check out this private site for map and site pics. http://www.nicoleanddebbie.com/casini/
The RV hook-up spaces are mostly out in the open in a large field where campers are lined up by the dozen within a few feet of each other.
The staff that I dealt with were friendly. The bathrooms were always reasonably clean. There was always hot water. No quarters were needed for showers, however the price is steep to stay here and most things in the store are marked up 300%. A box of "hardwood" (which we later discovered to be mostly pine with two or three pieces of actual hard wood) cost almost $14. It did not last much longer than the bundle of "pine" (some of it rotten and spongy, $7). You can also get an even smaller bundle of "kindling" little blocks of mill cut wood for close to $4. I recommend grabbing a bundle of oak or some other hardwood before getting to the area.
My favorite aspects of this place. The river has many shallow areas and is slow moving. The kayak rentals are reasonably priced ($10 an hour or $30 for half a day). They also have cool tractor pedal bikes that have back seats so you can tote the kids around for some sightseeing ($7.50 a half hour). My kid wanted to ride the bike the whole time.
Important note: this place is not in Jenner, CA. It is in Duncans Mills, CA which is about 15 minutes from Jenner. Jenner is a coastal town. Duncans Mills is on the Russian River in the mountains.
Travel tips? You may find GPS to be confused at times. If you are coming from anywhere east or south of Santa Rosa, take River Road and Hwy 116 from Santa Rosa west through Sebastopol and Guerneville to Duncans Mills and turn left on Moscow Road which is the one and only clear intersection in town (a four or five building town). Casini is just on the other side of the bridge about a half mile from Duncans Mills on the left hand side.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.