Online & site specific. We're pretty much always at State/National/County parks or COE campgrounds that are set up for online. They always send an email confirmation so you can have a printed record of what you signed up for. A lot will have fairly good details about the sites which helps if we haven't been there before, sometimes photos as well - Indiana even lists the distance to the electric post (necessary since they often share a post between sites). I'll also use Google Earth to try to get a feel for site placement, if the photos were taken when the leaves are down it works pretty well. The first time we stay at a park I'll go around the CG with a map and make notes of which sites I'd prefer for my next visit, which ones are good for groups, shading, etc. The only time I phone is when I need multiple sites at a Wisconsin state park since their online system will not allow you to reserve more than one site at a given park for the same day. No problem doing it by phone, and if you give them a list of the sites that you want they can block them out while they get all of your info so that no one else grabs them. Makes a difference when you're trying to get a group together at one of the popular parks in the summer or on a holiday weekend.
