How do I evaluate a source?

First rule of sources: don't simply claim bias. Bias means nothing without explanation and shouldn't be assumed, if you're going to dismiss a source because of this, you need an explanation such as 'this source emphasises the week point of King Henry VIII because at the time, the writer had just been exiled by the monarch's government'.

Step 2. Who wrote it, when and why. History is written by the victors or so we are told, bear in mind that not all sources are factual and sometimes the people writing them might not even have been there at the time.

Step 3. It's a picture and I have no idea whats happening. Breath, chances are in a real exam it will be in colour, enormous and wonderfully full of detail. Look at it's title, date and who created it, same as any written source. Now for the picture, what is it shwing? Is it realistic or stylised? was it created to incite anger or to inspire faith?

Step 4. Now that you have lots of lovely notes, order them and write them into several neat paragraphs with clear topics. It helps to cross the notes out as you write them down so you can be sure you haven't missed anything.