Whether you're an entry level DIY-er or a Pro, a Circular Saw is an essential part of your toolbox. Unfortunately, the standard blade that ships with most circular saws are referred to as 'Combination Blades' and are designed to cut almost every type of material you throw at it, with at best a mediocre finish. This is because most 'out-of-the-box' blades only carry 24 teeth and sometimes carry carbide tips to ensure a longer life and reduce the tendency for the blade to get stuck during use. This is called a 'thin kerf' design.
The More the Merrier !!
As a general rule, more teeth equals cleaner, smoother and straighter cuts. A 40 tooth blade gives a cut that is visibly better that a 24 tooth blade. However, if your projects call for cuts to plywood and other similar types of manufactured sheets or composite materials, you may want to invest in a 140 tooth blade.
Now you're cutting !!!
Also recommended to you "Easier Straight/Square Cuts".