PPPP

Is .us different than .uk or .com? I would expect it to be the same. Why no .us?

I took a few programming classes at university 10 years ago, but have only programmed in a unix enviroment, and mostly with C and C++. I'm by no means an expert programmer. I know almost nothing about programming in a windows environment. I'm looking for a book about using autoit that I can read on the train. Any recommendations?