Some good advice above but I'll just add one thing.
For my Ancient Hist A level, and later with Early Mediaeval history stuff at uni, i.e. courses where you have to remember lots of specific sources, I always found it really useful to make a tables dedicated to the sources.
There's a couple of ways I would do that. I would either list all the sources and then make a new row for each person/event they discuss (e.g. The reign of Emperor Augustus), with separate columns for:
- The general overview/opinion/point (e.g. Augustus was a good ruler, he built bridges, etc.)
- Any specific quotes
- Essay titles/topics they would be useful for
- Other sources that agree/disagree
Or I would organise it by having a different table for each person/event, with each source as a new row, including all the same information.
Which is better generally depended on the way the course/essays was structured and whether it was a source which covers loads of people/events (like 12 Caesars) or a source which covered one specific topic.
I would always colour code these too, either by person/event or by source.