Inspector Calls is the easiest of them all, if you're doing AQA that is. (Don't know about other boards)
The 40 mark question (only question on Inspector Calls) has two options:
1) A theme essay
2) A character essay
There are only 6 characters who actually speak in Inspector Calls, and they are the 6 only characters who would appear in the question.
Get key quotes for each character and relavent context and you're sorted.