Question: What is "heaven" like according to Christian teachings?
Response: Let me begin by pointing out that it is a common misapprehension that "heaven" is the final stop for believers. For "heaven" is very much a temporary place (see the link: "the Three Heavens"). The idea of the eternal future being primarily immaterial, other-worldly and unearthly is not biblical. This is fair to say even from a purely literary point of view, for anyone who studies the Bible as literature would have to admit upon a thorough reading that the notion of eternal life for human beings as angel-like, cloud-filled, extra-material, and heavenly-based finds its roots more in popular culture than in the Bible. In the Bible, bodily resurrection is the thing for which we are to hope. Indeed, the entire Christian hope is built upon this triumph over death - not some phantom-like half-state in another dimension - but real, tangible, bodily eternity, real life in victory over death. And this glorious life to come will not have its ultimate fulfillment in heaven, but on earth - the New Earth under the New Heavens, that is, with our eternal future focused on and in the New Jerusalem where Christ and the Father will dwell with us forever (see the links).
It is true that scripture teaches the temporary assembly of the faithful departed in heaven where God now is (cf. especially 2Cor.5). But what is commonly overlooked is that Christ is going to return to establish God's kingdom on earth (the Second Advent), and that, at the end, the Father Himself will return (see below) to an earth purged of all trace of sin and evil so that redeemed Man and sovereign God will live together forever on a now perfect and yet material earth (Revelation chapters 21-22 and Daniel 7 and 12 are the most pertinent references here).
This is a crash course on eschatology, and you have my apologies for the (possibly) confusing nature of it at this point, but it is an important segue into the issue you asked about. For the point has to be made in considering the issue of the after-life that, in true Christian teaching about eternity, the picture is not really one of a hazy, murky, hallucinogenic floating about on whimsical clouds, but of a bodily resurrection and of real, eternal fellowship with God on earth which is to be absolutely believed and confidently expected. We believe that Christ was indeed raised bodily from the dead, and the essence of the gospel is that all who put their faith in Jesus, faithfully following Him in this life, will likewise on the day of His return be bodily raised from the grave, given a new, incorruptible and wonderful body which will never die, and will share a blissful eternity with Christ on this earth (remade at the end of history).
The dilemma of human life, the sting of life, is that death is inevitable, and the reality for all who examine the question closely, who accept the existence of God (as our very natures and nature around us cries out for us to do), is that we are not good enough to stand before a perfect, holy and righteous God. But the good news in Jesus Christ is that God has solved this problem of problems for us, forgiving us our sins by sacrificing His Son for us and in our place. This astounding act of grace married God to the material world He created in an inseparable way, for now His own Son, true God in every way, is also true humanity, material as well as spiritual, and has successfully accomplished redemption for all those who turn to Him. The after-life is thus not an after-thought. Rather, it is the conclusion to which God's construction of history is fast racing. The corruption of the material world is temporary, creature produced (the rebellion of the devil) and creature propagated (the devil's current rule over the earth). But just as our bodies will be freed from the corruption of sin by being raised perfect and sinless, so the world will be remade at the end of time when God's victory is complete.
Thus, your question is really only answerable in a universal context. True, biblical "heaven" will be, in reality, a heaven-on-earth where we who have trusted in Jesus Christ will live with Him forever in real bodies, just as we do now, only better in every way and by degrees of magnitude now unimaginable. To experience this blissful eternity only requires putting yourself into the hands of the One who already has done more than you or can honestly imagine in order to provide it for you (please see the link: Salvation: God's Free Gift).
I also invite your attention to the pages on the website which deals with the resurrection, because, as I say, it is the resurrection that is the key both to the gospel of Jesus Christ and to any true appreciation of the Christian's eternal future as the Bible teaches it:
Peter's Epistles #20: The Resurrection
The Resurrection of the Lamb's Bride (in CT 5)
Please also see the following related links:
What does the Bible say about Heaven and Hell?
Last Things: The Millennium and the New Jerusalem (CT 6)
Hope this is in some way helpful.
In Him who is the resurrection and the life, our Lord and Savior Jesus Christ.