Unless your goal is to become an online personality or stand-up comic, keep everything on your social media accounts professional or private. Treat your online presence the same way you would act on a first date: be incredibly polite and present yourself in the best light.
Use Facebook for yourself and your friends, but make sure your privacy settings are set up properly, especially if you’re not going to be careful with what you post. Make sure your website, Linkedin profile and Twitter stream are completely professional and devoid of strong religious or political opinions. A little mystery is good at first. You never know who is looking.