It is such ages since I've done any reading on this that my best suggestion is to look at the reading list for Paper 4 of the History Tripos - section 15 is about the Civil Wars but some of the other texts might be useful for context.
Please can someone recommend a book about the civil war, i know nothing about this period of history and think i really should!
I've looked on amazon but there isn't really much to choose from, maybe i'm not using the correct search terms? I'm looking under english civil war (obviously although it throws up books about the american civil war too ) oliver cromwell and charles 1st. I've downloaded a few samples to try but most seem to assume you know something about this period of history and I really don't