Oh sheez, DH loves camping, we used to do it a lot before we had a baby. Our favorite place to camp is Bass Lake which is right before Yosemite Nat'l Park. It's great because the lake and river are right there and if you don't have a boat/jetskis, they have a rental place right by the water with very reasonable pricing and you can take them out for most of the day. They have showers near the camp grounds, I think they're $1 for 5 min? and the rangers are very nice and helpful.
About 25 minutes from the lake the main town has a theatre, big grocery store, gas stations and a few restaurants, so you're not that far away or too close to real city life. Also, Yosemite is 35 min nort of the Lake, just in case you want to go to the museums and waterfall attractions they have.
We used to go to Sequoia Nat'l Park or straight into Yosemite, but we like Bass Lake because everything is really close, we don't have to drive around or get lost looking for water or something to do.
Not to hijack but...I'm so excited that you have such wonderful things to say about Bass Lake- BQ. I will be going there next week for the first time. We won't be camping but staying in Oakhurst. Please let me know of any insider tips for me and the family. Thanks.
Twinkle, I'm not a camper but Pismo(which I guess isn't really South. Cali??) is really popular because you can camp on the beach, rent different types of ATVs, Quads, dune buggies, etc. There is also horseback riding. It's a nice quaint area.