My son shows our chickens in the 4-H and its typical to trim the nails and beaks before showing birds. I've done it on all our chickens and it's not that hard. I've only had to use a tiny pair of cat nail clippers, and I try to only take off a small amount at a time.
You can usually see where the "extra" growth is, by looking for the part that appears more translucent. Be careful not to trim the darker area, since that's the "quick", where the blood is. If it does start to bleed, you should pack the nail (or beak) with "Kwik Stop" which is a styptic powder. In an emergency, you could also use baking powder or flour. (My brother just called me recently for advice, when this happened with his dog's nails, and the baking powder did the trick.)
Some people also use a nail file to smooth the nails and round off the spurs, and to shape the beak after trimming. I've noticed when my chickens nails seem to need a trim because they start to feel too sharp when we pick them up. I usually check the beaks at that time, and remove the very tips that have started to overhang, just to help the "jaws" fit together better. It seems to help them eat better because they can grab small pieces of food easier.
I guess it depends on how much work you want to put into the care of your chickens. My parents never trimmed our chickens growing up, and they lived just fine that way; mostly free ranging around the yard. Theoretically, they're supposed to keep their nails and beaks worn down themselves, by scratching and scraping their beaks. This might depend on how hard the ground or surface is where they eat, however.