It's fun to make bread in shapes. A braid is a fairly simple shape too yet this one looks more complicated because of the multiple strands—18 in all. But don't worry, you're really only braiding three strands.
The sesame seeds are optional. I like the flavor, but the braid design is a little more obvious without them. You can still see the multiple strands when you're up close and slicing the bread, but the far view isn't as dramatic.
Chances are you won't have a precise rectangle of dough when you roll it out, and that's perfectly fine. When you're done braiding, you'll be trimming the end, anyway, to even up that end. You can use any leftover pieces to make a roll or two to sample your bread without cutting into the pretty finished loaf.
About the author: Donna Currie has been cooking for fun and writing for pay since the days when typewritten articles traveled by snail mail. When she combined those talents in a food column for a newspaper in her area, she realized that writing about food is almost as much fun as eating. You can find her on her blog, Cookistry or follow her on Twitter at @dbcurrie.