Twitter is a social media tool that is helpful for sharing links and latest events with people that follow you, the key is to get as many followers as you can so therefore more people see what you have posted, your website gets more hits the more you build up your following.
Facebook is a social media sharing website that you can share practically anything that is going on in your life with friends and family or publicly that everyone can see.
Pinterest is a platform for sharing things you come across on a day to day basis the more interesting your pins the more followers you will gain, when you see something you like pin it and it will show up on your profile for your followers to see. Another good way to drive more traffic to your website.
Google+ is in effect creating your own personal profile that you can add links to your personal websites, automatically sharing your posts too the Google+ community another great way to share your content and gain more followers.