i hear on fanpop some people asking about the last season they ask whether or not aang dies in the last season what is this season they are talking about is there a season four and does zuko find his mom can some one please answer me soon please

Aang does not die in the last season. It is a happy ending where he is with his mga kaibigan and Katara is his lady. :D Also, there is hope that Zuko finds his mom because he goes to see his father and asks where his mother is. That is how they leave it so we can assume that he will eventually see his mother again.
There is a season four coming out but it is going to be new characters and might possibly be many years in the future. Hope that helps! :D

He doesn't die in the last season.
The creators are actually starting a mini-series called The Legend of Korra [working title] which takes place years after the last season of The Last Airbender. Korra is the new awatara and it's Katara's and Aang's son that helps her master water bending. So, eventually Aang does die, just not in the last season.