Using a hole saw is the absolute easiest way to cut circles in wood for your project. All you have to do is lock your hole saw in the chuck of your drill or drill press and start cutting. You can use hole saws to cut circles from ¾ inches up to 7 inches in diameter.
A circular saw can't make a perfectly straight cut by itself. It needs a little help from a fence or cutting guide. There are four ways to make straight cuts with a circular saw. The four ways are with a speed square, DIY circular saw cutting guide, Kreg Rip-Cut or Kreg Accu-Cut.