Some truths you might as well realize early on.
First maps, are usually thrown away. (Well, actually they are shelved, cause game makers never throw anything away). That's just a fact, mapping is not hard, but it is time consuming and if you haven't done it before, expect to make mistakes. Expect to make quite a few of them. It's not so much that they're shit, but rather, by the time you've finished your first map you will have learned so much that the second one would be considerably better, more efficiently built, and a better representation of your talent. And since a lot of people get into modding to develop a portofolio for entry into the gaming industry, you want the best possible releases associated with your name. And if you don't think that matters, and you don't give a damn about the quality of your product, rest assured no one else will.
What's the learning curve like for Dedit?
If you have previous experience with 3D mapping, it shouldn't be too difficult, to incorporate what you have already learned and adapt it to these tools.
Since Dedit tools are the second set of tools I've had the fortune to work with, I find them very intuitive and quite capable for producing almost anything. Now if you are new to level mapping, it will take you anywhere from 40-100 hours to get a handle on the tools. This is directly a function of your ability to visualize things in three dimensional space. That's a couple weeks, working full time, at least a month if you're learning it after hours. I suggest you take a quick read of this brief article by Black Angel that's a good overview of modding in general. There are a few terms you should become familiar with.
Use the Navigation bar on the side here, they'll lead you to a set of tutorials that should help you out familiarize yourself with Dedit. I took time to give it a sense of order and chronology, following them should give the milestones to give you a solid grasp. Then again you might just be looking how to get a door to function so you can jump to it as well. Since I firmly believe that sharing information and wisdom is part of growth, I hope you find these useful.
I know you guys want to get into this in a big way, but take the time, and make sure you have a firm grasp on the basics before you move on to other topics. Everybody wants to move straight to AI and weaponry, but it is imperative that you make sure you build properly and without leaks. So these tutorials are set up in a logical developmental pattern. If you learn to build following basic rules, you will save yourself headaches later on.
Here are some additional notes I once posted on a forum:
Build in small chunks, components and prefabs, and then assemble it together as your project takes shape. Advantage? Small incremental accomplishments. You make something, you see that it functions properly, learn some stuff in the process, and then start the next component. It never gets overwhelming. If you build that way, you'll find that thinking through the creation of a level is easier. You'll then know you need a couple rooms, a corridor, an atrium. That's how the professionals do it, various team mappers build components and then they're assembled and tested. And if something sucks, then its only that component that sucks, its doesn't translate to the rest of the level, so that chunk is shelved, and a new piece is created in its place, compensating for whatever inadequacy was present. And you should always put something down on paper. Mapping is akin to archtitecture, in the real world you'd never build anything without blueprints. Its just a starting point, they don't need to be adhered to, but they are a step in the process. And to follow through on the analogy, building from the ground up makes a lot of sense, cause it helps towards scale, composition and space.
It's just a little advice. Take it if you want, ignore otherwise. But learn to crawl before you walk. If you get the basics down, the rest will just fall into place. The worst thing is having a map half finished, then realizing you've done things wrong, and will have to make efficiency repairs to actually make it playable on most machines. So like I said, most mappers usaully shelve their first level. And if they have the commitment to create a second one, they're on their way to becoming mappers.
Just a small addition.
Start with a small map. I don't mean small in size, but rather something that won't overwhelm you. Maps that are crammed with a ton of stuff tend to not run well unless they are fully optimized. Realize that the maps developed by Monolith for Multiplayer are sparse on details for a reason, they run better on line. Excessive interactive events, numerous polies in any one view, and bad lighting design and particle FX can all lead to laggy maps. Start small, finish it, move on.
My last analogy, you are not going to be doing algebra if you don't have the foundation of basic math arithmetic. Mapping is similar. Learn the basics first.