Also check out Wikipedia for a starting point if you want to learn more about Presbyterian history. I would begin with a search on the RPCNA. Pay special attention to the history section. From there do a Covenanter search. You should also read on the Bishop's Wars for a better understanding of what all of the fighting was about. (Remember Wiki is only a starting point, make sure not to use it for serious research since any person can have access to writing on it.)
There are also a number of books that are worth reading:
- Fair Sunshine by Jock Purves
- Our Covenant Heritage by AN Moore
- Scot's Worthies by John Howie
- The Scottish Covenanters by JG Vos
Make sure to read the first two parts of Glasgow's History of the Reformed Presbyterian Church in America for some really great information. He discusses the history of the Covenanters as well as the formation of the ARP in America.
Feel free to add links to other places of interest concerning the Covenanters to the comments section.