A good resume should be concise, but not too concise. It should highlight your skills, experiences, and accomplishments. It is also a good idea to make sure your resume matches the job you are applying for. You don't want to use a resume for a job that requires long-term experience or skills you don't have. A good rule of thumb is that if it takes more than five minutes to write out your resume, then it's too long!
Your resume will be treated like an advertisement by employers. They want to know why they should hire you over other applicants, so be sure to address this in your resume. You can also use the content of your resume as a call-to-action for potential employers: "Interested in working with me?"
Use bullet points instead of paragraphs when possible (the more information you include in one paragraph, the harder it will be for the reader to read it).