I must recommend http://www.mottolinesworldwide.com for anyone both citizens and especially foreigners visiting Nigeria for the first time to use. Actually this prompted me to work for the company during my internship in the United Kingdom. I studied Transport Management Technology in Federal University of Technology, Owerri.
http://www.mottolinesworldwide.com are an international company located in most major cities, Abuja, Lagos, New York, Ontario, Bangkok you name it. They offer online pre-booking service at cost effective rates. They are safe, secure and professional even the use of satellite navigation is their pioneering effort using this service in Nigeria.