valve adjustment really isnt all that hard to do by yourself. but if you're not too mechanically inclined then just take it to a honda dealership. i wouldn't trust a regular shop with it. I actually did it myself on my 01' and it only took an hour start to finish. If I had to ballpark a cost I would say youre looking around $150 to get it done at a shop.

oh, here's how to tell if you need a valve adjustment.... when your engine is cold, start up your car. open up the hood and put your ear up to the valve cover. if you hear a prevailant ticking sound coming from under the valve cover, that's your valves. no matter what, you can always hear your valve train moving, but if there is a loud ticking then your valve lash needs adjustment. I believe honda's service manual requires valve adjustment every 50k, but im not exactly sure.