Many years ago I was well versed in JW beliefs and practice. By the late 80's I had probably read almost every hardcover publication written by the Society since before the 1900's. I knew more about their Society, their history, and what they taught than they did. But, it has been a long time since I have kept up with them and the way things change in the society I don't what may have changed in their views.
The three doctrines you will be most often confronted with by any JW who shows up at your door will usually be either Paradise on earth, the nature of God or hell, at least this has been my experience. Often they will just begin with whatever the topic is in their most current issue of Watchtower magazine.
Here are some positions that were strongly held when I was keeping up with their beliefs.
Very briefly:
Their theology is decidedly non-trinitarian. They believe Jesus is a created being who was Michael the archangel before his incarnation.
In their eschatology they believe that the earth will abide forever and that the faithful will live forever on an earthly paradise. That only the 144,000 will be taken to heaven and rule a Princes over the earth.
Their soteriology is strictly works based.
They believe that man is a soul, not that man possess a soul.
They believe that Hell is strictly a figurative expression for eternal annihilation and that nothing of man survives beyond the grave.