It appears that there is a plain English "translation" or commentary on the ANO on the market. I have not seen the book, but here's a link to a description of it:-
http://www.flightstore.co.uk/the_ano...62.dept_l3.64/
Bear in mind that, as Al pointed out, the Order and Rules are amended quite often. According to the website, the book refers to the 1991 Rules of the Air, but these have been replaced by the 1996 version. It seems surprising that the book , published in 2002, takes on board the ANO 2000, but not the 1996 Rules (NB this may be an error on the website, not the book).
The CAA's own summary of the horridly drafted Article 130 (hotly debated in two threads running at the moment) is in my opinion a reasonably clear document.