We had our pool put in last month. Started planning in June 2011. We interviewed four pool companies and learned a lot from each one. Went with the one we were most comfortable with. We also interviewed 5 landscaping companies to do the interlock around the pool and in the yard. Cost for the landscaping was equal to the cost of the pool. We also did a fence, patio door and added a hot tub which were all extra. It was a full time job interviewing everyone and then managing them once the job started this spring. Just crazy. But its wonderful and it looks beautiful! We went with salt as well. Also did stone up to the rim of hte pool (over the apron). You need to make sure the stone you chose is guaranteed for salt water so that if you run into problems, it can be replaced as part of the warranty. It was a crazy learning curve but we learned more about what we needed and what to ask by interviewing pool and yard contractors. They know a lot and the more questions you ask, the more you learn and the more you can ask other companies to compare.
As for rules, we have three kids. Oldest is almost 10 so its hard to say no one unlses parents are here. Our rule is, if I'm the only one here, its our three plus 2. Doesn't matter whose friends. First two can swim, others its a no go. I can only watch so many at a time.