When visiting Transylvania (Romania) the very first thing you should know that we have limited number of motorways…, so do not plan to drive on highway during your journey. Instead be prepared to travel around “Eastern European” style, drive carefully, slowly and be aware of bears and cows.
Major airports are in Cluj Napoca, Targu Mures and Sibiu. When planning your trip always make sure to ask your hotel about possibilities how to travel from the Airport. The Aiport Shuttle is not yet common in the area, so it is a good idea to order a car or cab from your hotel, hostel. (always ask the price and agree beforehand).
You will find many ways to reach the destination from European cities to Cluj Napoca or Targu Mures there is a low cost airline Wizzair. From Bucharest you can reach Transylvania by train or buses. Find the train timetable here or you can plan your European train journey here.
The English language it is not yet spoken in the area, so do not be surprised when nobody can talk to you. In many places they will understand what you would like to ask but locals are not speaking good English. (similar to Spain) Of course there are some exemptions. The common language is Romanian, but you will find many people speaking Hungarian as in the Sekler part of Transylvania (Harghita, Covasna and Mures County) the majority of people living there are Hungarians. (I am not explaining here why, it’s history)
Even though nobody can speak the language you will find very friendly people who will help you to get all you need and you will be surprised by the hospitality of the people living in the region.
Hitchhiking is a common mode of transport in Romania in some areas. I would say drivers are used to hitchhikers so they would not be surprised and you can be lucky. You might think it is not so safe in Romania, but I tell you that I used to hitchhike (not so long journeys though) and nothing happened as a woman to me. Of course in most cases I would advice to not do it alone, find a friend or another traveler.