I did the mage stone at the beginning of the game but feel that leveling is already fast enough as it is that I dont need the boost.

Im on 360 - Can you 'turn off' your stone? Or go back to having no stone?

Get the shadow stone or something alike...it doesn't do anything unless you use the power.

Just choose another stone in Skyrim, like the lover and the ritual

There are 12 stones only 3 of them quicken levelling. I'd get the steed stone.

As far as I know, no you can't turn the stone off. What i'd suggest is getting a stone with no levelling benefit, like the serpent stone, steed, or the lord.

13 actually, acording to wiki, actually 4, the 3 early on and one you have to look more for.

I avoided activating any stone in the beginning and I don't regret it. As the OP said, leveling up is already too fast as it is. It's entirely possible: just walk past the guy and head towards Riverwood. The script will go on regardless.

As for the question, I'm afraid it's not possible. A good solution to the problem would be to activate another Stone which doesn't interfere with leveling up.

The steed stone is a great one, it gives you 100 extra carrying cap and armour doesn't affect speed.

Is there a list of the stones and their locations/powers? I have found a couple of others so far but would be good to know the rest.

http://elderscrolls.wikia.com/wiki/Guardian_Stones

Nice one, ta.