timing belt is not considered a 'tune-up'..:squint:
changing the timing belt is a major job, and should not be attempted by someone who doesn't know what they are doing.

But, it probably does need changing. If your timing belt does break while you are driving, it can cause catastrophic engine damage. Honda recommends they be changed every 90,000 miles, but i've seen them go for much longer.

A shop will probably charge you $300+ in labor to do this job, just make sure they change your water pump at the same time because it is right there.