You don't say where you live, but I would recommend Piedmont Yoga Studio as a good all-around yoga studio with many wonderful teachers. The studio is Iyengar in its orientation, which means it focuses on alignment and core strength. The students tend to be in their 30s, 40s and 50s, which makes it a welcoming place for a 40 year old beginner. Pick up a schedule for PYS and look for level 1-3 classes, then take a few to find a teacher you like. Raleigh Wills is a male teacher who came to yoga in his 50's, and he is particularly good at working with male beginners. Other wonderful teachers for beginners are Baxter Bell and Vickie Russell Bell. Good luck. nelly