Having a resume is an essential part of any job search. Resumes communicate on paper what you have done in previous jobs as well as any relevant education and training that would make you marketable to an employer.
Some key resume points:
It should be in electronic format to facilitate sending by email in an expeditious manner
It should be up-to-date, reflecting your current status as of today
Printed versions of the resume should be clean and professional looking.
Cover letters also help convey information to prospective employers that help highlight certain parts of your resume.