The bare-bones border crossing at El Florido (open 6 a.m.–6 p.m.) includes some basic services but little else. There are some snack and soda stands and a Banrural which changes dollars and travelers checks. Ubiquitous money changers are also on-hand to help you change your quetzales for Honduran lempiras. Note that many tourist places in Copán [1] take quetzales.
Crossing the border is fairly straightforward. If you’re driving a rental car, you’ll need to present a written letter from your rental-car agency allowing you to take the vehicle into Honduras. Otherwise, you’ll have to leave it at the border. As at other border crossings, you may be asked to fork over a dollar or two in the form of an “unofficial” exit tax.
Most Western nationalities, including U.S. citizens, need only a passport to get into Honduras [2]; no visas are required. You can either get a three-day permit to enter and visit Copán and vicinity only or request a 30-day or 90-day entry permit by filling out an official request form. It all depends on your nationality what length of stay you’re allowed.
In either case officials will probably try to extract a dollar or two from you, both on the Guatemalan and Honduran sides. If on a three-day permit, you can still use your original entry stamp into Guatemala upon your return to continue traveling for the rest of your stay in the country.
Once in Honduras, there are onward buses from the border to Copán Ruinas [3] every 30 minutes or so ($2). Heading back, the last bus from El Florido to Chiquimula [4] leaves at 4:30 p.m., but you are exhorted to cross the border much earlier in the day. To call Honduras, the country code is 504. Phone numbers are seven digits long. As in Guatemala, there are no area codes or city codes.
Links:
[1] http://www.moon.com/destinations/guatemala/el-oriente-and-izabal/copan-archaeological-site/copan
[2] http://www.moon.com/destinations/honduras
[3] http://www.moon.com/destinations/guatemala/el-oriente-and-izabal/copan-ruinas
[4] http://www.moon.com/destinations/guatemala/el-oriente-and-izabal/rio-hondo-esquipulas/chiquimula