Unitylc - for the amount of space to leave on each side the standard practice is 2 to 3 inches. When you have a pattern with that many pages, they usually begin upper left, then work across however many pages it is, then start second row of pattern pages. The pattern should show the order of the pages. Obviously you have a large pattern with that many pages and the system I described is best to keep from getting confused as to where you are in the pattern. I too usually started in the center - that is especially true of kits. But I find working large patterns starting upper left (after leaving the amount of space -- 2-3 inches from left edge and same from top edge) much easier to do. Hope this helps.

I don't have a problem finding the center of multiple page patterns...they usually have an arrow or indicator to simplify. But it is easy enough to do the math and mark it yourself. I make an extra copy and lay the whole thing out, tape it in place, and refold.
As for centering on the fabric, you have to measure the fabric and do the math with the measurements of your pattern. I like a 3 inch border, but have found that I don't always receive the exact width/length I ordered and have to trim to even everything up...nobody likes those kind of surprises. :)

I just have to start in the center and work out. So I make a working-copy and tape the pages together. (One working-copy is legal). I buy fabric by the yard and cut it generously.

When I am working on a multi page cover all pattern I start in the upper left corner and work the first page and then I drop down to do the page under the first page (along the left side border) and work all the way to the bottom as this saves wear and tear on the project. This way I only have to roll the left side as I continue to page 2 and down the project. I found if I worked across the whole top of the project I was constantly folding/unfolding/pinning/unpinning the fabric and it took quite a beating. Hope this helps. Take care and love your stitching.
cheryl

Like clplatt123 said when I am doing a very large project I start on page 1 3 inches in from the top and 3 inches in from the side. Like her after I do page 1 I drop down to the page below page 1 and work my way down the entire left side. I roll the right side while I am doing this and hold it with my very large quilting safety pins. After I get to the bottom of the project I start on page 2 and work my way down that column of pages. Like she said this way I don't have to keep rolling and pinning so much as I am stitching.

I always make 2 copies of my project while working on it. One is for taping and hanging on my design wall to mark off each page as I complete it and the other is for marking with a highlighter on my clipboard as I stitch.

Hope this helps.