After persecution and tribulation, after God's wrath and judgment, we arrive at the restoration of all things. The first thing we notice in Revelation is that eternity is not off somewhere in heaven but is on a renewed earth. "I saw the Holy City, the new Jerusalem, coming down out of heaven from God, prepared as a bride beautifully dressed for her husband" (Rev. 21:2).
While it is common to think of eternity being in either heaven or hell, we should realize that this is neither the predominant message of the New Testament nor the common position of Christianity throughout the centuries. I would not go so far as to say that this perspective has no basis in the New Testament (e.g., see John 14:2-3). But I would agree with the consensus position that the majority of the New Testament looks to eternity on a restored and transformed earth for those who serve Christ. 
Who will be present in this kingdom? Certainly those in Israel who believed in Jesus throughout the centuries will be there. Although John uses the image of 144,000 specifically in reference to those in Israel who remain faithful through the sufferings of the final woes, we can surely extend it now to all those Christian Jews throughout church history who have and will believe. These did not lie when they appeared before rulers, interrogated for their faith (14:5).
Also present with eternal life are all the Gentile believers. Then there are those mentioned in Revelation 7:9--"a great multitude that no one could count, from every nation, tribe, people and language." In keeping that Revelation gives multiple images of the same thing, we find this same group in 14:6. Like the 144,000, we can extend this image now to all of those Gentiles since Christ who have believed and will believe.
There is a reminder in this image that the gospel is not limited to one race, nation, or people. We are long used to the fact that Christ is not just for Jews. But Christ is not just for Americans either. Christ is for the immigrant in our land, whether here legally or illegally. Christ is for the Iraqi and the Palestinian just as much as for the Israeli. Christ is no less for the "white" as for people of color.  "God does not show favoritism but accepts from every nation the one who fears him and does what is right" (Acts 10:34-35).
John was of course writing just decades after the turn of the ages, just decades after Christ's sacrifice. The first group of resurrected that he has in mind are those who died as martyrs for Christ in his day (Rev. 20:4-6). When he next speaks of the resurrection of all the dead (Rev. 20:11-15), he probably is thinking mostly of those who died before Christ. Those who rise to life were those who were faithful to God given the light they had. He primarily has in mind individuals like Noah and Abraham and especially those within Israel like Moses and Elijah.
Given how symbolic Revelation is, we probably shouldn't separate these two resurrections in our sense of how God will literally restore all things. After all, no other book in the New Testament speaks of two different resurrections. We as Christians simply believe that, at the end of history, when Christ returns to renew and judge the earth, the dead in Christ will rise to serve the Lord forever, including those who were faithful according to the light they had in the time before Christ.
If we are not to separate the two resurrections in our sense of how history will literally play out, we should probably take the picture of the millennial reign of Christ as somewhat symbolic as well. Traditionally, there are three perspectives on the Millennium of Revelation 20:1-6. In recent times, the "premillennial" view has been very popular. This view takes Revelation 20 more or less literally and sees things getting worse and worse until the end times. Then Christ will reign for a thousand years literally after the judgment pictured in Revelation.
However, throughout most of Christian history, the predominant view has been "postmillennial." This view more or less associates the millennium with the age of the Church these last two thousand years. If the premillennial view tends to be pessimistic and see things getting worse and worse, the postmillennial view tends to be optimistic, seeing the Church as the means by which God is getting the world prepared for the kingdom of God.
Given how symbolic Revelation is--and given the fact that John was primarily addressing the Roman Empire and the struggles of his own day--perhaps we are best to take a more "amillennial" view of things. The amillennial position does not restrict the millennium to a specific period of time but recognizes that there have been times in the last two thousand years when Christ has reigned more and times when he has reigned less. Most of all, he will reign for all eternity.
Again, since Revelation is the only place in Scripture where a millennium is mentioned, we probably should take it mostly as a symbol for Christ's eternal reign. But Christ has also reigned over his true Church these last two thousand years, and he must reign in all of our hearts individually, even though Satan is still on the loose. It is, after all, striking that John's imagery allows for there to be some who are lost even after the reign of Christ (e.g., 27:8).
John's picture of the final city of eternity is surely also full of symbolism that we will not fully be able to understand until the end. The image is clearly one of immense beauty and happiness.
Who will be part of this everlasting kingdom? "Those whose names are written in the Lamb’s book of life" (21:27). These are those who are covered by the blood of the Lamb, those who have kept God's commands and remained faithful (e.g., Rev. 14:12).
There is no temple in that eternal city, the new Jerusalem come down to earth (21:22). The earthly temple was always just a copy of the throne room of God. Now there is no need because God himself will dwell with humanity (21:3). There is no need for sun or moon for God himself is our light (21:23, 25; 22:5).
There will be no more sacrifices for there will be no more sin. The curse of Adam is gone (22:3). The Garden of Eden is restored and the Tree of Life is now available as originally intended (22:2). We are not in a position to know exactly what this all means literally. God gave John these spectacular images to give us just a taste. What we know for sure is that we don't want to miss it!
 N. T. Wright is probably the scholar most known for renewing this understanding of the New Tetsament. See his Surprised by Hope: Rethinking Heaven, the Resurrection, and the Mission of the Church (San Fransisco: HarperOne, 2008) and his more extensive, The Resurrection of the Son of God (Minneapolis: Fortress, 2003).
 "White" is a fairly recent category that grows as groups that were initially immigrant become more accepted. So a century ago, Americans were Irish and Dutch and German and English. Now all of these are artificially put together as "white," in contrast to black, a category more or less invented during the slave trade of the 1500s and 1600s. There is no black and white in the Bible, only Jews, Greeks, Romans, Scythians, Egyptians, Babylonians, etc.