When you talk about shutting off, do you mean that the screen goes dark after you've been looking at it a while (and not touching it)? And, to start it back up again, you need to press the Sleep button (on the top, opposite the Home button)?
If yes, you may just need to adjust your AutoLock settings. Do do, go to your Settings app and, within the General area, scroll down until you see the line "AutoLock." Press on that line and you will then see you have several times to select from. Pick one that will give you more time before the iPad goes to sleep.
You can even select "Never" - but that may make your battery run down faster as the iPad will, obviously, never go to sleep (dim the screen) until you choose. Sometimes, I select Never when I know I need the iPad on for a while - but I set it back to a certain time length when I'm done.
Hoped this helped.
Marilyn