1st hand of 1st deep stack tourney

[stone_7]

This was from the 30+3 stars on Monday night. I have been mulling this one over for a few days now and I am still not sure I know what I should have done.

First hand so everyone has 5k chips. I am in the big blind.
I am dealt A 5 of spades. 4 limpers and the sb completes so I check. Flop is A A T with 2 diamonds. I check it through to the button who bets 100. sb folds and I reraise to 300 or so. One guy in the middle and the button both call. Next card is the 2 of diamonds. Pot is 1000 and I lead out for 800. MP folds and Button calls. River is a complete brick and I check. The button goes all in. What should I have done here?

Sorry I don't have the hand history but I am at work and don't have it handy. Once I get some answers I will post my reasoning and result.