I get this question a LOT. It seems that over the past several decades advice on the topic of resume length has varied. I've had clients absolutely insist that they must not exceed three pages. Others jump right in and write a novel
The truth is that length isn't the issue so much as quality. Your document should be a cohesive and succinct overview of your greatest accomplishments and most valuable skills. It should declare briefly and compellingly what you are known for and how you have demonstrated that in the jobs you've held.
Your resume needs an easy-to-read format. It should contain bullet points, used judiciously. The font should be easy to read. There should be enough white space to ensure it doesn't look cluttered.
It should say enough to communicate your point, without going on too long.
Keep in mind that you are in control. You can decide what to include and how to phrase it, and where to place the information. The goal is to ensure the reader can instantly see that you fit the company's needs and why. The goal is simply this: To show you as a candidate worthy of an interview.
It's not as complicated as you think. Give me a call and I can give you additional pointers.