Getting the map would certainly help a lot.
But like what Beeker said, feel free to go back and look around again.
It's a bit more tedious in the water temple since there are some rooms that you can only access depending on the water level.
But there are a lot of hidden rooms in that temple...
I just cleared the water temple recently, so I can probably help you. =)
You'll need to be a bit more specific, though. What is it exactly that you're having trouble with?