For each internship or job, include the name of the organization where you were employed, the city and state, the title of the positions held, the employment period for each job (include both months and years), and a short description of your accomplishments and technical skills used, listed in 3-4 max bullet points.
This might seem obvious, but it is very important. Make sure your resume is updated with your most recent contact information. Recruiters and hiring managers often get thousands of resumes for one job position, so providing them with your email address, personal phone number, and home address will make contacting you for an interview much easier. When including your email address, be sure not to use addresses that are too casual.