You will see that "My Broadcast" has two icons -'Preferences' and 'Profile'. Profile lets you change your avatar from the default, give yourself a byline, and edit personal information. Preferences let your edit the description and tags of your broadcast, set your privacy level, manage your subscriptions, change your password and view your list of groups.
Tags are words that describe your work. Adding them to your broadcast is the easiest way to have others find you. Select the 'Preferences' icon in 'My Broadcast'. In the 'Broadcast' tab you will see a place to add a description and below that a place to enter a list of tags, called 'Topics'. Enter as many as you want, separated by commas. You can also add a tags widget to your page - this shows other people your list of interests.