The NOR is posted at
http://naf18.com/wordpress/wp-content/uploads/2008/03/2008-naf18-nor-v4.pdf - the entry form is the last page. Paragraphs 3.6 and 3.7 explain how to send in your form.
If you plan to swap out crew, it isn't a problem as long as you let the Race Committee know ahead of time and the swap doesn't require you to change sail plans.
Pensacola Beach is a great place to sail, and you will definitely learn a lot at a championship - study up on the rules ahead of time because the mark roundings and start line can get very busy. Other sailors expect you will know who has right of way - if you don't react the way people expect you to, it could get hairy.