Citizens of the United States, western Europe, Canada, Argentina, and Chile are not required to have a visa and are issued a tourist visa on arrival in Honduras [1]. Authorities are currently granting 90-day visas, and any extensions (30 more days are available) must be taken care of at the immigration office in Tegucigalpa [2]. Citizens of all other countries are required to obtain visas before entering Honduras.
Foreigners are required to carry their passport with them at all times, but rarely if ever will it be checked.
No vaccines are required to enter Honduras, but travelers should be up to date on their rabies, typhoid, measles-mumps-rubella (MMR), tetanus, yellow-fever, and hepatitis A and B shots.
Honduras has three international airports, in Tegucigalpa [2], San Pedro Sula [3], and Roatán [4]. The first two receive daily flights from Atlanta (Delta), Houston (Continental), Miami (American), San Salvador, El Salvador (TACA), and San José, Costa Rica (Copa). Spirit Airlines also services San Pedro Sula. There is weekly service to Roatán from Atlanta, and twice-weekly flights from Houston.
Driving to Honduras from the United States (or elsewhere north of the Panama Canal) is certainly possible, particularly for those with a good command of Spanish. There is also twice-weekly boat service between Placencia, Belize [5], and Puerto Cortés [6].
Transiting between the main destinations in Honduras [1] by inexpensive public transport or a private car is not difficult, apart from in the Mosquitia. The main highway system is generally in good shape, although be prepared for a lot of long, bumpy rides (sometimes in the back of a pickup truck) if you head out to more rural areas. The Bay Islands [7] are easily reached by frequent airplanes or ferries from La Ceiba [8].
Links:
[1] http://www.moon.com/destinations/honduras
[2] http://www.moon.com/destinations/honduras/southern-honduras/tegucigalpa
[3] http://www.moon.com/destinations/honduras/central-honduras/san-pedro-sula
[4] http://www.moon.com/destinations/honduras/the-bay-islands/roatan
[5] http://www.moon.com/destinations/belize/the-southern-coast/placencia-village
[6] http://www.moon.com/destinations/honduras/the-north-coast/puerto-cortes
[7] http://www.moon.com/destinations/honduras/the-bay-islands
[8] http://www.moon.com/destinations/honduras/the-north-coast/la-ceiba