Definitely include your volunteer work. Volunteering gives you not only experience but also awesome recommendations from the people you meet that you can put in your resume or job application. I find it a great opportunity to network and meet people I usually wouldn't meet otherwise.
Make sure your resume is organized and triple check for grammar and then have a friend check it.
When I wrote my first resume, I felt like I was bragging about myself, and I felt guilty. But in the end when I finished my resume, I could see all that I had accomplished. That part made me feel good :)
Also, do not forget to add a "skills" section-this can include any relevant skills, such as languages (are you bilingual?), computer and software competency, html, cpr (if relevant) etc.