Log into your control panel and download the client:
Click on the Newshosting .dmg file that you just downloaded to start the installation. Drag the Newshosting app to the Applications folder in the popup window. The Applications folder itself can be opened by double-clicking on the folder in this window.
Once the install is complete, launch the client from the Applications folder. You will be prompted to log in with your username and password unless they are saved.
Once logged in, you can start searching right away!