A few quick tips (ones that you will probably see in a Google search, but here they are anyway):
Keep it short, one page or less--The average employer spends something like 30-45 seconds looking at a resume before deciding whether he wants to interview you. Which means anything on page 2 or later will probably not be read.
Keep it simple--Bullet points and short sentences are your friend. If you are describing a previous job/experience and your description is over two lines long--it is too long. You can use your interview to go into more detail on anything you deem important.
Highlight the positives--If you had a good GPA in High School/any college classes, mention that in your education section. If it isn't the greatest, then there's no need to put it there. Any future interviewers who are interested will ask about it, at which point you have the opportunity to explain that even though you weren't the top of your class, you are a dedicated worker who is willing to learn, or talk about some things you gained from your education outside of grades. Also, make sure to highlight any awards/commendations/etc. that you received in your education/previous positions.
Have someone review it for you (ideally someone who has experience in interviewing and applying for jobs)--You want to make sure everything is spelled correctly, with correct grammar, and that all relevant points are clear. People can rarely be good judges of the clarity of their own writing, so having someone else help you is important.
Hope that helps!
