Open your favorite internet browser and navigate to the YouTube channel or playlist you want to track, then copy the link to it into the clipboard.
Run YouTube Downloader, open its Preferences dialog and switch to the Tracking tab. Paste the link into an appropriate field and click the Load button. The program will download all necessary information about the channel.
Click the Track button to subscribe to all future updates of this channel.
Now you can configure additional options, such as automatic adding to the download queue, changing the destination folder, specifying the playlist and update interval. On the picture below we selected the adding option, so all new tracks will be automatically added to the download queue upon next check. You can also select save as audio option to save only audio stream, it's useful for podcasts, audio books and of course music.
The status bar icon displays that the channel tracking function is active. The icon will turn red if the program finds new videos. You can also refresh channel information manually using the menu item Update now.