Have you been scrambling to get everything else in your life done, but have been putting off filing your taxes?
Below are the links for CA state and federal and a brief explanation of the consequences if you don't apply for an extension.
Fill out the extension form with the pertinent information Name, Address, SSN, etc. This will give you a 6 month extension to file your tax returns. You still need to pay now or you will be charged interest on the amount that you still owe. These forms extend the period you have to file the paper work.
If you know you owe and send the estimated payment in with the form. If you don't pay April 15th you will be charged interest on what you haven't paid.
Hope this explanation helps.