Does the preceptor need to sign the affiliation agreement or just a representative from the institution?

The preceptor does not need to sign the affiliation agreement. The person signing must have the authority to sign on behalf of the facility and their employees. For example, at a high school, signing authority might reside with the principle or superintendent, at a clinic it might be the CEO, etc. For colleges/universities, it is usually a president, dean or their designee. There may be a contracts office at the college/university that handles these types of agreements. Remember if the preceptor is employed by one facility (i.e., a clinic) and is supervising students at another facility (i.e., a high school) then there must be an affiliation agreement or MOU on file for both facilities.