References. It is assumed that you have references if you have previous employment history. It is not at all necessary to include “references available upon request”, adding this is actually a potential deterrent. Potential employers will ask you for your references later on in the interview process if they see fit. Of course, if references are asked for within the application process, provide them - just not on your resume.
Only include your GPA if it is higher than 3.5 on a 4 point scale (no need to mention that 2.0 when you moved into the frat house sophomore year) and only if you are a recent graudate. There are a few exceptions to this rule, like if you’re applying for a job in academia or engineering where a GPA is expected. You can also list honors or awards if you’re a recent graduate. If you attended college, but did not finish your degree, list the number of credits obtained. For recent graduates, education and internship are your main selling point. But if you’ve already been in the workforce, tone down your education section, the best rule of thumb is that one line will suffice.