Revelation 21 gives a detailed description of the New Jerusalem after it actually lands on the earth (i.e. after the Battle of Armageddon). We have not bothered in this book to detail the gore that accompanies the "seven vials" of the Wrath. You can read about it in The Revelation, chapter 16. Unfortunately, despite all that God does to get their attention, the world still does not repent. Instead, they become more bitter against him. They eventually unite in a fierce war against God himself. (See the next chapter.)
The Bible tells us that there will be no marriage in heaven. (Matthew 22:30, Mark 12:25 and Luke 20:34.) This is a bit hard for most people to imagine, as marriage seems to be the closest to heaven that most of us ever experience here on earth (although some would say it is the closest to hell too!) However, just as we cannot fathom how God could do many of the things that he has done (e.g. Creation itself), so it is hard for us to comprehend the far greater pleasures that he is yet to give to those who put their faith in him.
The Bible tells us that God will provide the Light in New Jerusalem. The physical presence of Jesus, ministering to millions of different individuals, is hard to picture. But through the combined assistance of the Light (God's spiritual presence) and his heavenly hosts (the angels), Jesus will apparently be able to meet the needs of all his faithful followers without any problems.