The primary definition of Pentecostalism is the doctrine of arminian pelagian salvation, with some believing in baptismal regeneration. In some circles, more specially those I was involved in, there is an open and blatant denial of the Trinity, Jesus name baptism, and humanistic holiness standards. Most pentecostals also believe that tongues are the initial sign of baptism of the Holy Ghost.
There can also be declared two branches of the movement as a whole, not excluding the separation between Oneness and Trinitarian Pentecostals. It is the division of Conservative and Charismatic Pentecostals. Many within the Pentecostal movememt fall into either one of these categories. The Charismatics have the demonic signs of animal demon manifestations in their believers, as well as fake supernatural manifestations (gold dust, gold teeth, oil developing on the hands). Many conservative Pentecostals do not carry these 'experiences' as legitimate.
Within the next few weeks, I am going to be working on a book. Pray for me to stay dedicated to this, as a tool to help people out of the Pentecostal movement, and to avoid it all together.