The Rules for Mordheim
The Mordheimer's Campaign Aid
Along with tons of other downloads at the same site, here.
And a great Mordheim Forum with which to interact with others at Tom's Boring Mordheim Forum.
Now those are great places to start. There quite a few more that I am sure you can search for and find. The biggest hurdle for everyone when it comes to Mordheim is terrain. If you are lucky and have the money, then you can buy quite a bit from sites on the internet, such as:
of course Games Workshop
Other wise you may have to make your own:
Works in Progress
Really all you need is some poster board and a good knife. Design some walls, cut them out, glue them down, and paint it up. This is really the best way as you can create some great terrain this way.
Need inspiration? Gidian Gelande and his their Mordheim table...AWESOME!!
You really do not have to go so far at first. Build up your collection over time. Have a building party at your house or your local gaming store. Even better, see if the store would be interested in hosting. What you really want to do is get the rules down, so the games will flow better. Run a few games, get your feet wet, hash out ideas, and think about what extra warbands could be used in a campaign.
The most difficult part is getting other players involved. This is an old game. This is not the latest version of Warmachine or Infinity. The system is very forgiving and it's easy to get started. Just buy a box of generic warriors from what ever race you want to play, and you have most of your starting war band right there. You can split the cost with a friend, as there's usually more than enough for a single band in a box. Admittedly, some of the figures are not as customizable as they used to be. You may have to be creative in modeling a great weapon, a bow, or other bit. Remember you can always substitute or even use Elmer's Poster Tack, found at your local grocery store/office store, to attach other weapons and items with.
A bit of background on my part, I created the first campaign set back in 2003 and have used it several times since. I posted it online at various forums for others to use. There really wasn't anything out there like it then. Each time it gets tweaked a little bit. The Mordheimer's Campaign Aid was the latest version. The biggest change to that was the actual Mordheim map.
Feel free to use any or all of the links provided. Grab some friends and get started. Visit and use Tom's Boring Mordheim Forum. Just be sure to post pictures. We all like to see pictures. Most of all, if you find this post helpful, have questions, or find it to be utter nonsense, let me know.