On the form, the college asks you if you want to waive your rights. If you do, you will not be able to see the documents even after you enter college. I strongly advise you to sign the waiver.
The reason is this: By signing the waiver, you are effectively telling your recommenders that you are confident of what they are going to say (since you won?t know if they wrote nasty things). Colleges see your confidence as a good sign. They will trust that the letter is more truthful and candid than if you had not sign the waiver. If you are concerned that your recommender might be negative in his or her recommendation, then that is a sign that you probably should find another person.
After you?ve given your teachers to sign the form, always provide them with stamped and addressed envelopes so as to make things easier for them. Approach them early and give them ample time to prepare your letters. Follow up once in a while.
Lastly, update your teachers on your admissions status. They?ve helped you write nice things about you, so you should keep them posted on your progress. It?s just pure courtesy.