We will need some more info on what is happening to your pad. Have you tried a reset? Hold the power off button and the home button simultaneously, keep holding them in and you will see the power off slide appear and disappear, wait until you see the Apple logo appear before releasing the buttons. It will take a little longer for your iPad to start.
The IPad Forum is a community of members from all walks of life and from all over the world coming together to share our experiences and to help each other learn about this wonderful piece of technology the Ipad. There is a wealth of information already here in the many threads we have so doing some searches will answer most of the questions you have. If then you cannot find the answer you are seeking then by all means post your question. There are many friendly and informed members here only too willing to help you.
...also, might be worth checking to see if your Auto-lock is set for 2 minutes. I wasn't sure by reading your post if you actively using your iPad and it shut off on you or if you had it on and walked away for a minute to see the screen black.
Go to settings/general/auto-lock. You can increase the time before if switches off(sleep).