Sources play a vital role in the study of History. It is important to know how to engage with the sources correctly and use them appropriately in an answer. The three main things to remember are:
1) What is the source saying? before anything else, look at the source itself and try and work out what exactly it is depicting/talking about. Often there is an accompanying text which will give an overview of what the source is about
2) What ideas can be taken from the source? with a wider knowledge of the History course, themes may appear that you can discuss in a bit more detail. Even if you dont fully understand what is happening in the source, try and pick something out that you can relate back to aspects of the course
3) Be detailed. It is often hard to keep to the time limit in an exam and also get everything down that you want to write. The best answers are always concise - not necessarily lots of information but always relevant to the content of the source - quality over quantity!