Simulating Cell differentiation
Trying to answer this question in a few lines is a tedious task. Mostly I'm not sure that as of today we know all there is to know about it.

I'll try to give you some hints though.


The process is called embryogenesis. The zygote (or ovum) undergoes rapid mitotic divisions with no significant size growth which will lead to the development of an embryo. This process is called cleavage. Blastomeres are created during this process. On the third day - time may vary but not significantly - cleavage reaches the state of 16 cells. Cell divisions always occurs by parallel division (1 -> 2, 2 -> 4, 4 -> 8, 8 -> 16). Study the links I gave you and come back with more specific questions.
Again that's kind of impossible question to answer without explaining the entire process from fertilization to fetal development, because creation of tissues (cells) and organs happens along the way, not at once. However, it's documented.
Not sure.
Start with the wikipedia links and try to come back with more specific questions. I have a couple of text-books but I'm afraid they are not as detailed as you would want :-)


Good luck!