I have been ruler quilting for a couple of years now. I would suggest the Sew Steady website for purchasing ruler foot and rulers. I know there are many other makers of ruler feet and rulers but I would start with Sew Steady. They will make sure that you get the correct foot for your machine and they have YouTube videos showing how to use the different rulers. They also have Sew Steady University with classes and projects to use your rulers, sign up is free and many of the classes are also free. Do not purchase rulers/feet off Amazon as many are knockoffs of Sew Steady or other ruler manufacturers, they are poor quality and could possibly damage your machine. I also just completed HollyAnne Knight's Free Motion Quilting Academy and I do believe my knowledge of using rulers helped me learn, I use my ruler foot when free motion quilting as it gives me the option to change between the two when quilting tops and I feel that it did help with speed/stitch control. Also make sure you purchase the right ruler for your foot (high or low shank) as a high shank ruler will not work on a low shank foot as it is too thick but a low shank ruler will work on a high shank machine. Another good place for rulers is Angela Walters, her rulers are high quality and she now has both low and high shank options and she has lots of YouTube videos demonstrating her rulers. I love my rulers and hopefully if you decide to start ruler work you will too, like other types of quilting it will be frustrating but remember practice, practice and practice.