1. Use quotations sparingly. They must make grammatical sense in the sentence.
2. Make sure to analyse them after using them - otherwise they are worthless.
3. Use them to back up an argument you have already made, or to dispute an argument you have made, allowing you to come to an alternative conclusion. Good use in introductions and conclusions can also help make your essays punchy!
4. You do not need to use quotations - the mention of schools of historiography shows in depth knowledge of the subject matter.
Some examples:
1. To back up a paragraph's argument - below is the abbreviated paragraph.
'' The Republicans lost the Civil War as much as the Nationalist won it due to their political divisions, while the Nationalists remain united throughout...The May Days of July 1937 where there was open fighting on the streets of Barcelona between the CNT, Poum, PCE and PSOE clearly demonstrates this. Paul Heywood also supports this argument, stating that 'The Republicans were at war...with much of the world...most importantly they were often at war with themselves.' This shows that it was not only nationalist unity that led to their victory in the Spanish civil war, but that the Republican effort was significantly weakened by their disunity. ''
2. In an introduction (abbreviated version below)
'' According to the Revisionist view, the USA's polices were hugely responsible for the outbreak and development of the Cold War in the period 1945-1949...However, we must consider X. I will therefore discuss A,B, C and conclude with support for the Post-Revisionist view that emphasises Y. ''