The way I see it there are several types of mods

-Full scale conversions

Major projects that explore a new era eg. Napoleonic, Medieval etc. and therefore must create a whole new set of models and layout but essentially keep the same basic game mechanics. Although they are not limited to the basic structure and often change game balance to implement new features, guns for example. These require a team that can communicate with one another to best fit the needs of the project rarther than the aims of one person. Sometimes large teams can build their own communities, for example the lordz

-Partial conversions

These are mods which stick with the same era but may have a different starting date and finishing date. Examples of these types of mods are TFT and the hun invasion, model changes are fairly low and these mods tend to rely on new skins to give a different feel to the game. These often incorporate new game balance and sometimes base mods

-Small scale conversions

Usually taken on by one person or a small team these change a few aspects of the game intended for personal use but are often shared with the modding community. Examples are making all build times 0 turns and editing the battles so they are longer.

-Base mods

These focus on a particular element of the game and modify the mechanics to provide a different gameplay experience. Examples are ZoR and the more than two turns a year script. These can be included in other mods and are aiming to be a help to the community (My Zulu mod will use both ZoR and the more than two turns a year script)

-Expansions

These expand on the current game or aim to make it better, examples are EB and RTR


There are also many differnt types of modders

-directors (organize a mod, however not limited to one per mod)
-modellers (shortage of these and essential to full scale conversions)
-skinners (also essential but a greater supply of these)
-text editors (edit text files for general use)
-scripters (very few good scripters however not as essential to most mods)
-historians (only needed for historically accurate mods, can often help several mods)
-animators (again very few but most modellers know how to do simple animations)
-media/graphics (most skinners are good with graphics but media and advertisment can be quite tricky)
-the community (essential to almost all mods they can contribute greatly)

There are other people that help out in mods as well providing research, doing the campaign map, web hosts etc. but I don't think that there is a set pattern to becoming any of these as I am a modeller and animator but can't edit text files very well.

As far as my Zulu mod operates, we all contribute ideas in our forum in a special bit for private development where members of the team can express their opinions. Once we decide that we are going to implement an idea we tell the community and see if they like it. I am the organiser of things and I do the modelling, animations and some skins but I have to rely on others and I think that's a big part of every team. You need a system to carry on the momentum and keep the mod alive. If you look at some of the mods on SCC, for example the American conquest, they are struggling because they have no modellers. I'm not saying it's going to die but now many of the modellers are comitted to other mods and only free up when their mods die. Of course there are freelancers as well who just do modding for the fun of it and whos models or skins can be included in big mods.

One idea of mine that got very little interest (none ) was to create a library of models and skins that could be put into different mods. I think this would help some mods by providing them with a couple of screenshots to get their mods off the ground.

These of course are only my views and certain mods may not fit into that mould