I used to draft wills for a living. It can be a good idea to number the pages (e.g. 'Page 1 of 2' and 'Page 2 of 2) but it's not a requirement. However you should never staple or pin the pages. (Just keep them together by placing them in the same envelope, remembering to ensure that your executors know where to find it!).
The same applies to a codicil. (Just put it in the same envelope as the will).
If you need help in preparing a will, I strongly recommend getting hold of a copy of this book. (It's in many public libraries; it won't matter if you get an older edition as the essential stuff about drafting a will hasn't changed). Even if you plan to use the services of a solicitor, it's still well worth reading first:
http://www.amazon.co.uk/gp/product/1844900703