Life Before and After Death

I am currently reading a book about how a psychiatrist'd life is affected by one of his patients whom he analysed and his belief changed about reincarnations and life after death. He explains with ease thats how he using hypnotherapy made his patient remember the previous life she lived..I should say that i was quite moved after reading the book though i have not completed it. But sure i am filled with more questions about it, i mean is there any limitation of the life form and soul form in numbers? Or they can just keep on multiplying, Does our karma really guide our fate? And if we resist doing something what role does karma had behind it?
When we act in favour or against someone are we exactly influenced by our previous life ? And what about the new persons if any whom we meet?
How do we get free from it?
And what about the time in between the death and next life ? What exactly do we learn from it?
Although i know that there aremanythings about which we dont have any explaination and we cant go on exploring answers to all the questions generated cause of the moral bindings of this physical ( i dont know what else to call it as ) world, but if something like that really exists how exactly are we going to find out if what is happening is cause of our karma or of someone else?
For now i really dont have any answers, but i am sure curious to read the book and certaibly i have got more intreseted in the field of psychiatry, may be i will become one.
Well i guess i will come back with more questions and some answers, for now. Bye.