Hey,
I would first look at the source and get the main ideas from it (usually about 3-4ish). I would highlight those points, summarise into my own words and say if I agree/disagree. I would then pick historians that would correspond with the main arguments of the source. So, in this way you can't really only choose three historians to study and memorise but have to know a lot more.
I know it's really hard to memorise these historians but I made a lot of flashcards, and for homework I have to do tables for the historians with headings such as the ones on the syllabus such as:
Who are the historians?
What are the purposes of history?
How has history been constructed and recorded over time?
Historian’s Interpretation on their subject
Why have approaches to history changed over time?
What impact has the historian had on historiography?
What are some of the criticisms of their approach?
Hope this helps
Susie beat me to it, but this is a different view-although her's sound really great!!
AWESOMMMEEEE! Some great suggestions here Katie

Especially love you flashcard idea - sounds like an awesome study method!
Hey Susie,
What are the major debates that we should know? Also, is it good to talk about our major work in the essay as i'm not really sure if they would know who my historians are? Who is John Vincent-is he someone that we need to know (my class hasn't studied him-is he important?)
The major debates/issues that I suggest having a look at are:
- Can history be objective? (so empiricists v. relativists v. postmodernists)
- Should history be objective? (empricists v. postmodernists)
- Popular history v. Academic History? or Public v. Private history?
- Social History (pros and cons)
- Role of imagination
- Role of popular culture
- Nature of evidence - only official documents?
Those kinda things

I'm sure you can think of a tonne more as well! It is DEFINITELY a great idea to talk about your major work - it doesn't matter if they don't know about your historians, YOU know about them, which means you'll be able to provide a super sophisticated and thorough analysis of them + you'll be going beyond the conventional, seen-them-all-before historians like Herodotus and Von Ranke. Some schools may study John Vincent, but not every school! My school didn't, I just read some of his works - he's a really great source, deals with the nature of evidence and social history really well!