Keep it away from dust and water, don't leave it sitting somewhere freezing or boiling hot, and stay out of direct sunlight—that’s basically it. Just wipe it down with a slightly damp cloth and dry it off immediately. Or use those specialized screen wipes or electronics cleaning sprays.
Look, there are plenty of tutorials on YouTube showing you how to crack open just about any laptop, but if you've never done this before and aren't particularly handy, don't try it yourself.
Usually, you only need to clean a laptop once you notice it starting to run hot. If it’s been running in a clean environment for two years without spending all its time sitting on a fuzzy blanket or something that kicks up fine debris, it probably doesn't need anything yet. But if you notice it getting warmer than usual or, God forbid, throttling while you're doing heavy tasks, then it's time. At that point, you have to decide whether to DIY or pay someone. If you go the DIY route, make sure you actually watch a teardown video first, get the right tools, grab some thermal paste, and good luck...
As for repair shops, any decent one should be able to handle it without an issue. I know a couple specifically because they actually stock replacement LCD panels and handle reballing/reflowing, and they advertise cheap cleaning services too:
http://www.geekgadget.com/Of course, that assumes you're in New York City, since you didn't specify where you're located...
