The best choice for concrete pools is tile. You can also easily replace individual tiles by yourself, so it's easy to maintain. It usually costs about $50 to do a DIY repair.
Once the primer has dried you can apply the topcoat epoxy, or resurfacing product to the pool. You should paint the pool from the depths to the shallows, according to the manufacturer's recommendations. The topcoat should dry completely before you apply your next coat. You should sand your pool between coats in order to make sure the next layer sticks properly. The average pool needs between three and four coats. This may take a few hours, or even overnight depending on how hot it is.
It doesn't matter what type of pool you have. All pools need to be resurfaced at some point. Here are the details on costs, methods, and materials.