your resume is supposed to be just 1 page....you dont need to write everything you did since the time you were born...if you are an undergrad, you are supposed not to mention any highschool's achievements unless they are extraordinarily exemplary :)
as long as content,,,the general format is
Education
honors/awards
work experiences
Leadership/Activities
Skills

These are the main sections..the experience should cover most of your page at least half..

Just keep in mind that your resume will be skimmed for 30 secs
dont make yr resume look like packed...use action verbs ..explain what results you brought more than what you did..
hope this helps