Before you start groaning, know that having a solid resume is probably one of the most important things you can do when looking for a job in the IT field. This is your one chance to display who you are, what you do, and how you can be a benefit to your future employer. In short, it's your chance to make a good first (and perhaps, only) impression. Take it seriously and you're bound to get more interviews and job offers than if you just brush off the task.
Write Well
This might sound overly simple, but really you need to present yourself professionally on your resume. That means writing clearly and succinctly. It means avoiding typos, spelling errors, and grammar mistakes. It means taking the time to ensure you've made your resume the best it can be. Nothing will cause a potential employer to dismiss your resume faster than spotting tons of errors. Don't let this happen to you.
Customize Your Resume
It's a bad idea to make one generic resume and send it out to every employer. Sure, you can have a resume with basic information, but you'll need to modify it for every job you apply to. Try to get a sense of who will be evaluating your resume at each company. Adjust your tone depending on the employer's website and goals. If the job listing asked for specific traits, experience, or qualities, bump those up higher on the resume so they're more noticeable. This will make you look like a natural fit for the position. Also, cut out parts of your resume that don't fit with the job you're applying for or just don't emphasize them as much. If the employer requires experience with Ruby, detail how you've worked with this technology early on. List out other technologies you've worked with later in a bulleted list.
Keep Your Eye on the Goal
What's the point of a resume? To get you hired, right? So try to keep that in mind as you're constructing your IT resume. How are you the best candidate for the job? What skills do you bring to the table? What experience have you had that makes you uniquely qualified for the position? Try to think about your innate qualities and things you've done that will set you apart from other applicants and how you can make yourself irresistible to the hiring manager. Make yourself appear vital to every company you've ever worked for and you'll go a long way toward bumping your resume up to the top of the list.