Question: I'm looking for the best possible guide book on Iran.
What am I looking for in a guide book to this specific country is good and up-to-date practical advice on accommodation and transportation.

Answer: www.uppersia.com has gathered all your needed information about Iran. You can aslo ask the staff about your questions. They will answer you back in less than 24 hours.

Lonely Planet is also a good guide book around Iran. The offset copies are available in Iran for cheap.