Israel, Palestine, and Repatriation

I don't normally get into this controversy, but with all the concessions, counter-concessions and agreements floating around today, I'm reminded of a couple of long-standing questions I've always had about this conflict.

As far as I can remember the actual history of this subject was never taught in my schools, nor did I have any classes that touched on it in college. While I'm sure there are tons of research material available...hey, this is the 2000's and I want it in nice, neat digestible chunks, so here we go:

• After the end of World War II, it's obvious a lot of Jewish people had lost their homes and ways of life from Nazi rule. I'm assuming from memory that the Allies decided to resettle a lot of these people in what is now Israel. I'm also assuming there were a number of Palestinians living there at the time, and they were removed to allow the Jewish refugees to settle there. Under whose control was Israel at that time, and under what authority (moral or legal) did they use to remove one group of people to settle another?
  
  
• Why exactly is it imperative to the Jewish people that there be a "Jewish State"? I don't usually hear calls for a "Christian State" or "Muslim State". I understand the desire to live in their ancestral homes and control the Holy Land, but what is the basis for the need to maintain a state that is primarily and legally Jewish?
  

Well, I apologize for my profound ignorance of World History on this subject - it's one I'd like to rectify and if there are any good texts someone could recommend I'd appreciate it.

By the way, Donald Sensing has a good analysis of the day's proceedings, and how the Palestinian population problem threatens Israel's existance through sheer numbers.