The Haby Goddess: Tutorial: How to sew on bias binding ~ the trick to making sure your second row of stitching catches the back bias edge is all about the first stitching line and not the bias itself. NICE tips!
Understanding Thread Tension on Your Sewing Machine
Sew a circle easily THIS really does work, have used the idea for years! Perfect circles each time. Use a tin or bottle lid a little smaller than the circle you want to sew, with sandpaper attached for grip.