Hi
Present day Rumania is composed of three major parts: Walachia, Moldavia (not to be confused with the Moldavian Republic, which is more or less only a part of historical Moldavia) and Transsylvania.
Transsylvania was a part of the Kingdom of Hungary throughout the Middle Ages. Walachia and Moldavia were independent principalities established in the 14th century, to a certain degree under alternateing Hungarian, Turkish (from the 15th century) or Polnish (in the case of Moldavia) control.
I can't tell you that much about Walachia or Moldavia, mainly things like who ruled when, whe fought with whom and basic stuff like that, but not things like how people lived and so.
But if you are interested in Transsylvania too, let me know, and if I find the time, I'll write some things up for you.