****
I dont know why people skip prolouges... It depends on the book I guess. For some prolouges they don't make sense at all and I might deside to skip it, but usually I do read the prolouge. I sometimes find prolouges pretty intresting and how they actually tie into the book.
****
I expect the prologue to hook me!
****
I don't think I've read a novel where the prologue wasn't necessary. To me, it's just like another chapter. Sometimes there's a vital key or hint to the story in there and you won't understand until you finish the novel and then I go back and say, "Oh, that's what that meant!" So I think it can be a clever way to sneak some information in there, sort of get the reader intrigued about the story.
****
I think it depends on the prologue. I think I like when they go back to their childhoods the best.
****
I like a good prologue as long as it adds to the story but they are not needed. Sometimes I've read prologues that take away from the story. Here is a good article on it:http://www.foremostpress.com/authors/articles/prologue.html
****
I read all prologues on the assumption that, if the author put it there, it's important to the story. Many "prologues" should simply be renamed "Chapter 1." In my opinion, a prologue should be different in time and/or place, but closely related to the main story. A brief setting-of-the-stage, so to speak. Not all books need a prologue. A great opening line accomplishes so much more than an unnecessary prologue.
****
Only write a prologue if it is necessary. There is no right or wrong about it. So the question is does your book need a prologue?