Even though this question might seem a bit odd, it's actually a real question. I do wonder if you always start directly from page 1 or if you jump towards the mid section of the book or even the last couple of pages, before you actually start reading the entire book?
I personally usually read the last page of the book, or the cover on the back of the book, before I decide to read the entire book or not. No matter if it's a guide, report, ebook or an actual paperback book.
I've done this for years and I guess I do this to see if I get some sort of "feeling" for the book or not. In case I don't, then I won't read it. In case I get something, then I'll read the entire thing. From page to page.