Every time I speak to a group of people, and people talk to me afterwards, the topic of résumés always comes up. And every time people ask about résumés, someone always asks "Does my résumé have to only be one page?"
Your résumé does not have to be limited to only one page. It just needs to have nothing irrelevant and uninteresting in it.
I refer to film critic Roger Ebert's rule about how long a movie should be:
"No good movie is too long and no bad movie is short enough."
You should apply the same rule to your résumé.
As long as what's in your résumé is relevant to the reader, and the reader finds it interesting and it helps show how you'll be a valuable addition to the hiring manager's team, you can put in whatever you want, and your resume can be as long as you need it to be.
This means that when you apply for a job as a network engineer, you don't bother mentioning your job at a pet store back in college, unless it somehow relates to the job for which you're applying. If the job for which you're applying is at PetSmart corporate headquarters, then by all means, include it.
Is anyone reading your résumé going to care about your "hobbies and interests"? Probably not. I guarantee they won't if your hobbies and interests are "music and reading." On the other hand, if you're looking to do web development for Guitar Center and you play an instrument, then definitely put that in your résumé, perhaps even in your professional summary.
This also means that you have to tailor every résumé you send out. You have to go through every line and think "Will someone reading this résumé care about this?" You have to figure out if some bullets in your work experience should be expanded.
From today forward, don't ask "Is my résumé too long". Instead, inspect every word to see if it is of interest to the reader.