There are some medical nasties associated with neck pain, including meningitis and heart attack. Having a look at the neck pain section at the Mayo Clinic (opens new window) would be worthwhile if you want to make sure there is nothing seriously wrong. So would a visit to your GP or MD.
Neck trouble (something wrong in the neck that doesn't necessarily hurt) may cause pain somewhere else, not in your neck-- for example, your shoulders and hands.
Currently back-pain-self-help.com has the following neck exercises. Like all our exercises they're very gentle.
As an Alexander Technique teacher, I observe that almost everybody holds the top of their necks very stiffly. We don't nod between our ears, but further down our necks, using smaller, more vulnerable joints. Although this is "normal", there is nothing "natural" about it, and in many people it leads, sooner or later, to neck pain.
As children, most of us used all our spinal joints very effectively. Some people, often those at the peak of their professions, use their entire spines beautifully even as adults. They include dancers, boxers, musicians, public speakers and acrobats, as well as many others in less public spheres.
When your neck is wrong, very often other parts of your back don't work properly either. If you have a problem with your neck, your lower back and middle back have to compensate, and in time they too can get sore from doing a job they're not designed to do.
Your back works best as an integrated unit. You will find that exercises for your neck inevitably help other parts as well. For myself, working on my neck has been helpful for symptoms in my lower back, hands and arms.