Check out this video from Frank Hiedt in it he explains the most common ways companies and people get hacked.
+ Don’t use the same password for every site/service.
+ Keep your software auto-updated (keeps you safe from known exploits) – particularly Adobe Reader.
+ Hold email suspect from those people you know that ask you to do unordinary things like open a file or log in to a website.
Start with the basics and level up in tightening your security.