First of all if you are applying for next summer you had better ger your application in now. The bulk of hiring is done after the Denver job fair which takes place every April. The best advice I can give is to go to the job fair, meet the people who do the hiring and then keep in touch with them. As you can imagine they get swamped with applications. You need some way to keep yourself out front. Be persistant without being a pest.
The other thing is to be ready to go at the last minute. People always flunk the physicals or decide not to go and every year the program is left scrambleing trying to fill spots. If you are debt free enough to drop everything and leave at a moments notice then by all means let everyone know. See the discussion thread I’ve been having with Prairie Dog about what to expect later.