It was called the Anarchist Cookbook (based on a 1970s book) and sold online.
News report states he sold over 3000 copies in a wide variety of countries.
Apparently his intention wasn't to arm and teach terrorists - it was purely financial and... er... very short sighted:
BBC News - Portsmouth man guilty of publishing 'terror handbook'
Lets hope that his buyers were like the guys in the IM niche who like to buy products and NOT take action ;-)