Since I'm considering switching jobs, I thought I'd throw together a few tips on getting a new job in IT. At the risk of sounding like a job hopper, I've switched jobs 4 times since starting my career 8 years ago, and I've started to learn some tricks. In IT, it seems the best way to get a raise is to get a job offer. In my experience, a job offer is the very best way to negotiate a higher salary - It shows that your skills are in demand and makes your organization consider the costs of replacing you.
1. Never let your network go dormant. It's far easier to get a job from an inside tip or with a reference from inside a hiring company. Make new work relationships, keep the ones you have, and never burn your bridges. People have long memories, and you never know who you'll end up working with again in the future. IT is a small community - Use that to your advantage.
2. Polish your resume, and keep it up to date. Find a good, clean looking template, and use it for your resume. I use a 2 page CV with some background, projects with skills utilized, experience, and education. Every time I finish a project, I update my resume so I don't forget what I've worked on in case I see something I need to apply for in a hurry.
3. Practice interviewing. Interviews are important. Treat them as a challenge with their own skill-set. It may seem unfair, but sometimes people that interview well will get offers over applicants with more experience and education. Accept interviews from opportunities that may not be a perfect fit just for the practice. I know someone that has no intention of leaving his job, but tries to get an interview per year just to stay sharp. Always try to learn from every interview you do - Especially those that don't result in offers. Also, if you have the opportunity to be part of the recruitment process for new candidates, get as involved as you can; It gives a new perspective when you're on the other side of the desk.
4. Talk to your references. Before you give references, make sure they know the situation. Call them, ask if you can use them, and make sure they're suitable. Give them an idea of the position you're applying for, and provide them with some talking-points. It's a huge advantage if your references are impressive and on-message.