In the body paragraph you will basically express your interest in taking admission. Important things you are going to mention include the basis for applying to the school. Why do you think this school can build up your career? List down all academic achievements and special skills that would help in making your letter stand out from rest of the applicants.
The lawyers add that: "This is the legal problem with a Letter of Intent _ you can't legally state you agree to something and then state that you don't in the same document." Famous Case of a Letter of Intent Gone Bad: Court Case of GETTY OIL vs. PENNZOIL