Once at a site you will have to make the decision as to whether you want to hire a guide. It depends on how large the site is, if you have a good guide book in hand, and how comfortable you feel on your own. We only hired a guide at Copán, since it was our first site. I was glad that we did..... Oscar (our guide) explained the significance of the various buildings, stelae, and inscriptions that we saw, and made the experience more worthwhile. We also spent some time with a guide at Tikal on our first day there, another good choice. On the second day we explored on our own. At the other sites we did not use or need a guide, though we could have used one at Yaxchilán. Oh, and don't forget to tip them at the end of the tour.