I recommend any books by Lavinia Stan. She was born in Communist Romania and has dedicated almost her entire academic career to the study of it, although her PhD is in Polisci and not history.

This film isn't that informative as there's no narration and even no sound for a good half of it. I think you'll find it interesting nonetheless; it's a long edit of an absurd amount of archival material from his ascent to power to minutes before he was executed. The section on his visit to North Korea is gorgeous(and the silent 8mm footage of him cheating at volleyball while nobody says a word is hilarious).

The Autobiography of Nicolae Ceaușescu