There are plenty of surprises that come with the experience of death, but the top two might be these: 1. that you go on, and 2. that who you truly are has absolutely nothing to do with the body you think you are leaving behind. The more you can get comfortable with these ideas while you are alive, the easier the experience of death will be.
During this life, you might have thought you were your body. You may have identified yourself by what your body looks like (ie, I am tall, blond, blue eyed, and soft around the middle), but the body is an image; it is not you. It is a character in a dream; it is not you. It is a picture in the mind; it is not you.
It is true that the body seems to die, yes; it tends toward entropy, but only because that is what the mind expects of it, or because at some point we've begun to see death as a welcome respite from the stress of the world. For some people death begins to feel like the only way out from under the clouds that have taken up residence in the mind; there seems to be no way to fix what needs fixing, and death eventually becomes a preferable idea to the continuation of the current state. For other people death is simply the experience of what we expect; we believe we are personalities inside bodies, we have watched other bodies age and die, and we simply believe on some level that this is what must happen to us as well.
But no matter what you believe about it, death is nothing more than an idea we experience via perception. We have the perception of death of the body, and yet we do not die, because that body is not who we are. Ultimately there is no reality to death because what we are in truth — awareness or spirit, or love — never dies. Because God exists, death cannot.
The experience of death can be frightening, however, if you are not prepared for it. The process of it unearths all of the fear we hold about leaving our family and friends, all of the attachment we have to this world and to this particular version of reality, as well as all of the guilt we have about things we’ve done or not done, said or not said. Because of this, some people find the experience rather challenging. But if you are prepared for it, if you decide to face your fear and spend at least part of this life getting ready, it can be much easier.
Everyone has an opportunity during the process of death to return "home," to return to the Oneness that is the eternal Truth of things. Without preparation we tend to miss this window, because there is too much going on in the mind. With the cultivation of a peaceful mind, however, we can get off the hamster wheel of this life and wake to the awareness of our own Oneness with God, which is Love.