Some good advice to be sure, but I've noticed one thing: everyone has something different to say...
I don't think there is any right or wrong way to play AA, the bottom line is to win the pot. With that said, there are so many different variables in any given game that there is no set way I would play them. Stay within your strategy for that particular game, and remember to change up often. For example in a freeroll, I might slow play the flop, then turn it on at the turn. I try to avoid the all in if it's the beginning of the tourney, because there's ALWAYS
more than one jackass that's willing to call you with his 73 and 72 off, and one of them will beat you on the river. Not quite every time, but damn close.
I'm not a big fan of going all in early in the tourney, because it takes any skill right out of the game, and leaves it all to luck. I, personally, am not willing to chance my entire stack on 100% luck early on in any game...usually.