First introduced as an article entitled City of the Damned in the official Games Workshop magazine (White Dwarf #223), Sneak Peaks of the Mordheim table top game began appearing within White Dwarf as development rules until the box set Mordheim came out.
The boxed set included the official rulebook (first printing), building templates and several plastic sku's to make the beginnings of a Skaven and Mercenary warband. Seperate boxed sets of buildings (Blood on the Streets boxed set) and individual warbands came out in response to popular demand.
The official magazine of Mordheim, the Town Cryer was first published as articles in White Dwarf. Popular demand gave way to printing the Town Cryer articles as stand alone magazines starting on Issue 7. These quickly went on back order with the price increasing dramatically for late comers.
Games Workshop collaborated several spin off game magazines into one publication under the title Fanatic for Battlefleet Gothic, Blood Bowl, Epic, Inquisitor, Mordheim, Necromunda and Warmaster. The magazine was controversial since the followers of the separate games felt, at any given time, that other games were receiving more attention.
While most of the article publications are flavor text, showcases of warbands, techniques of crafting and general generation of excitement about the game, all actual game content was eventually published for free to download. The Games Workshop site doesn't support Mordheim anymore but the popularity of the game keeps files, articles and fan-based content on other web pages still today.
There were two major publications besides the original official rulebook. The Mordheim Annual 2002 included many republished rules from Town Cryer articles that were considered the backbone of added content in a paperback form. Empire in Flames was another paperback reprinting of the countryside terrain rules outside of the walls of Mordheim.