Tonight I watched episode 704 - Cricles, Curves, and Chocolate with Dale Fleming. She demonstrated how to do stitched curves her way as well as making the Six-Minute Circle. HGTV has a tutorial on making this six minute circle. It has possibilities for doing lots of different shapes. Dale's book, Pieced Curves So Simple, is in my bookshelf! It's a great book with lots of easy to follow photos.
YouTube has lots of video demos on sewing curves.
How to Quilt, a Beginner's Guide to Quilting shows you how to sew curves in your quilting.
How to Make the Perfect Drunkard's Path Block
Sewing Curves with Jinny Beyer