Love the comment from other pinner, "How to use a double needle tutorial.shut up! This is amazing. I learn new sewing stuff all the time!" The other thing I didn't know is the double needle seam stretches.
Pattern Drafting Tools and their functions :: By: Isn't that Sew Read this has some good tips. If your starting out just buy the essentials. Tip: Measuring Tapes check against metal rulers every so often they will stretch after frequent use.