The first five verses in chapter seven point to another author than the last chapter. Instead of two-by-two, God tells Noah to gather up seven of every clean animal and two of every unclean. (From what I understand, the clean/unclean thing wasn't stated until Moses came down off the mountain, so this seems kind of anachronistic.)
We also find out that Noah is six hundred when the flood happens.
It rained for forty days and forty nights and the earth stayed flooded for a while after. Everything that didn't live in water died. "The Lord wiped out every living thing on earth; man and cattle, the creeping things and the birds of the air; all were wiped out from the earth. Only Noah and those with him in the ark were left." (verse 23)
Chapter eight starts by saying that the world was flooded for a hundred and fifty days (!) "And then God remembered Noah..." and started the drain. (I've always wondered where the water came from and where it went during this.) Seven months later, the ark gets caught on the mountains of Ararat, but it takes another three months for the tops of the mountains to show up above the water.
The next six verses are how Noah figured out land was coming back. First he sends a raven, which doesn't do much, then a dove several times. Eventually, the dove comes back with an olive leaf. (It's been almost a year since the land has seen sunlight. How the hell was there an olive tree? It should be dead.) He sends out the dove again and when the dove doesn't come back he figures that things are returning back to normal.
In the second month of the 601st year of Noah's life, the earth was dry. God tells Noah to let everything off the ark and that they should all start multiplying to refill the earth. Noah sets up an altar of thanks and sacrifices one of every clean animal and bird and God seeing this decided never to do something like this again.
