Do you mean how do you install them?

If that is it, then what you do (I use CS 2, so it may vary from version). If your brushes come in a .zip file, unzip it first. Then start Photoshop. Then select your brush from your tools. Now click the drop down brush menu that lets you select your different brush tips. Then you will notice this little silver-white circle with a triangle in it. Click it (you might have to right click it). It will give you a menu. Select Load Brushes. Go to folder where you unzipped the brush file. Select it. And there you go. I hope this is what you wanted to know!