Find the ABR brush set you'd like to offer. Go to your desktop, right click and create a compressed (zipped) folder. The reason we create a compressed folder instead of automatically uploading the actual ABR file is because it will decrease the risk of direct linking and stealing of your brushes. It won't necessarily prevent it altogether, but it is a better alternative to offering bare ABR files.

After you've made your compressed folder, drag your brush set inside.

Now all that's left to do is simply upload the folder to your website. After you've done that take the URL to your folder and create it into a link. Pretty simple, right?