...
Facebook Privacy Settings
Facebook in constantly changing its privacy settings and policies, so it's important to be on top of your own profile. Do you want to be able to be searched? What do you want non-friends to see? Do you want your boss to see those pictures of you playing beer pong? Should those pictures even be on your page? These are all important questions to ask yourself about your Facebook page. It's important to be responsible for what other people can see about you online. In the end it's your chose what to show on your profile, but be sure to be proud of what's there.
Twitter Privacy Settings
Twitter makes it very easy to keep your profile private. If you protect your tweets, people cannot see them unless you accept a follower request from them. All requests have to be approved first, so you will know who is looking at your tweets. Be careful about accepting strangers because you never know who they may be.
Branding Yourself
...