Palau's only town is Koror, with about 10,000 people who nearly all speak English. Palauan postage stamps are colourfully collectable. Letters take a week to ten days to North America. January through April is the dry season and the best but busiest time to visit. You will need reservations during those months.
Camping is fine out in the Rock Islands.
Hotel and restaurant prices are a little bit lower than back home. Most mid-priced hotels are in busy Koror and convenient to shopping, eating, and bars. If you have to ask, you can't afford it. Add ten percent tax to all room prices. Groceries and most products cost a bit more than back home.