hello Crolson, I'm a born-in JW, middle aged now, so know the doctrines well (but have rejected many of them). I still associate occasionally (for my husband's sake) but inside no longer consider myself one.
Anyway, here's the basics... They believe in an Arian God (no trinity) whose personal name is Jehovah. that he's the Almighty with a balance of qualities such as love, wisdom, justice and power. Jesus Christ is the Son of God but created by God, as a prehuman they believe he was Michael the Archangel. They believe he was solely human while he was on earth (albeit perfect, like Adam). They believe he was resurrected as a spirit (not a physical body, they believe that was consumed by God). Any body he had after his resurrection was a materialised one the same as they believe the angels have. They believe Christ is a ransom buying back the perfect life Adam lost, so that they can have perfect life again forever on a paradise earth. (Only 144,000 get resurrected to heaven). Death is the end of life, non existence. A life can only be regained by resurrection in the future. Salvation comes by belief in God and Christ, putting faith in them, dedicating oneself to God (meaning having to preach, attend meetings etc) It is a very works based religion... (although caring for the poor and needy is not that important, preaching is). Salvation also comes by being part of what they consider 'God's Organisation', one has to be faithful and obedient to it. Anyone that doesn't, won't have salvation and will be destroyed at 'Armageddon', God's war against mankind. After this war the earth will be restored to a paradise under God's Kingdom (Jesus as King along with the 144,000 resurrected from the earth). God's Kingdom is a government that is in heaven. During 1,000 years all the dead will be resurrected to earth along with the nucleus of the 'Great Crowd' (Jehovah's Witnesses) that survived Armageddon. After the 1.000 years anyone who doesn't worship God will be destroyed (again). All their teachings come from their interpretations of the bible, along with all their publications, especially the Watchtower magazine. The Holy Spirit is seen only as God's power, impersonal but can guide us. Sin is a missing of the mark of perfection inherited from Adam. It will only be completely gone when man becomes perfect at the end of the 1,000 years.
Hope that helps :)