18 LPI or less checkering set
I would recommend you start out using a 18 lines per inch checkering set or fewer LPI for the learning process. If you choose more LPI, you might have trouble learning to keep the tool working in a straight line. I recommend Gunline checkering sets as well as the Miles Gilbert checkering set. The Gilbert set has very ergonomical handles and a set of learning coasters as well as a video that gives very good instructions. MidwayUSA sells the kit in 18LPI. The Gunline sets can be had in any pattern and once you learn how to checker, you can buy additional cutters to add to the handles that will allow you to cut different LPI patterns.
As far as books go, get the checkering booklet that Midway sells to begin with and then get the checkering book that the booklet recommends. If you want to learn to checker, I would go slow and let your muscles learn to pattern in a straight line on coasters or pieces of hardwood like old throw away stocks first before you pick up a good stock. It took me several tries before I got where I could cut a complete pattern out without messing up frequently, so don't expect to come out of the gate swinging for homeruns, it just doesn't happen that way. I also suggest you get a checkering cradle or build yourself one as well. It wil become your friend very quickly if you have one.
Once you learn how to checker, you can go over the pressed checkering patterns and turn them into checkerd stocks as well which will turn a sow's ear into a silk purse very quickly. Good luck with it. About the only other advise I can give you is once you learn how, don't just put it down or you might end up having to relearn the whole process all over again because muscle memory plays a big part in checkering.
