1) camping skills - how to stay warm and dry and have food and water
2) navigation skills - how to get from A to B without getting lost
3) planning skills - survival is to a great degree avoiding survival situations - which is a great degree due to good trip planning. A well planned trip is also a more enjoyable trip!

However, if you want to write a best-seller, plan poorly and have an epic - that is what seems to sell nowadays!