Ethiopian Airlines flies to Addis Ababa from Washington, D.C. (703/572-6809 or 011-251/11-665-6666, ethiopianairlines.com, round-trip fares run about $1,270, including taxes and fees). Travelers must reconfirm all flights from the point of departure. This is true for internal flights, too: All visits within Ethiopia will be interrupted by a trip to the airline office, unless your hotel sends someone for you.
The weather is warmest and driest between October and mid-March. Plan ahead if your visit is during Timkat (in January), or Meskel (in September).
The towns are small, so there aren't really addresses. If you're looking for someplace specific, the easiest thing is to ask. Many people speak English.
Tukul Village Hotel in Lalibela is on the main road, on the south side of town (011-251/33-336-0564, $39). Government-run hotels, meanwhile, are booked most easily through a travel agent or the Ghion Hotel in Addis Ababa (011-251/11-551-3222, www.ghionhotel.com.et).
Any hotel can arrange a guide--who often ends up being the man who met you at the airport. Terekbe Mersha can be reached at firstname.lastname@example.org or 011-251/911-034-463.
Outside of a hotel, a restaurant, or the company of a guide, you won't spend a few seconds without getting asked for money. Develop a thick skin, and consider donating to a local charity.