For the post of an Administrative assistant or executive, you need to specify the details completely of pertinent use to the employer so that he can easily identify with the necessary skills for the post of an Administrative assistant.
Your Administrative Assistant resume may be made up of the following important points:

A brief and an accurate summary of your credentials
Education, job experience ,achievements and goals
It should be able to flow naturally and be easy to decipher and read.
 

Administrative Assistant

Coordinate and perform a range of staff as well as operational support activities for the unit; serve as a liaison with other departments and operating units in the resolution of day-to-day administrative and operational problems.
Provide administrative/secretarial support for the department/division such as answering telephones, assisting visitors, and resolving and referring a range of administrative problems and inquiries.
Operate personal computer to compose and edit correspondence and memoranda from dictation, verbal direction, and from knowledge of established department/division policies; prepare, transcribe, compose, type, edit, and distribute agendas and minutes of meetings.
Schedule and coordinate meetings, interviews, appointments, events and other similar activities for supervisors, which coordinating travel as well as lodging arrangements.

An Administrative Assistant Resume must be able to process the information mentioned to the best of his interests. For this reason, it's a good idea to keep your resume updated after each major task, accomplishment or qualifications received. Keep up to date with all your qualifications job contracts and job descriptions.

The following will help you to write your resume.

Contracts
Job Descriptions
Periodical Performance Reviews
Letters of Reference
Letters of Appreciation
Qualification Certificate's
Specialist Courses
Mention job descriptions in the chronological order starting from your current job and going down hence. This shall embark an excellent impression on the employer as it shall reveal how your job responsibilities as an Administrative Assistant have further enhanced over the years ever since your first employment.