There are three basic tools that are used to make MOH: AA maps.
They are MOHRadiant (in MOHAATools), MBuilder, and Pakscape. It is possible to get the same effect as MBuilder by building your
own compiler, but for these and the following tutorials MBuilder will be used, so I suggest you download it.

MOHRadiant can be downloaded here: MOHRadiant at qeradiant.com
MBuilder can be downloaded here: MBuilder at FileFront
Pakscape can be downloaded here: Pakscape at FileFront

If by some chance those files are taken down, hopefully you'll be able to find them by doing a google search!

Starting with MOHRadiant.

MOHRadiant is like any install application. Just run the .exe and install. Reading any 'readme' files at this point is prefered, but incase you skip over it, I'll try to give some basics.
In the MOHAATools.zip, there are a few tutorials. You are free to read those but I'm going to assume you're not going to.

After MOHRadiant is installed go to the directory you installed it to.
There will be a file called entdefs.pk3. You must put this file in your MOHAAmain folder.
After that, you can run mohradiant.exe in the directory you installed it to. It should ask you to confirm/enter settings... At least it used to for me, now it won't.
But if you don't feel like answering to anything then don't. Certain things must be set, however, it's just harder to explain them from the first time you run mohradiant.

After it has loaded it should look something like this:

Click on "File" in the toolbar and scroll down to "Project Settings."

Assuming you used the default install directories for your MOHAA game, this should resemble what the boxes would contain:

basepath: c:/program files/ea games/mohaa
mapspath: c:/program files/ea games/mohaa/main/maps/
autosave: c:/program files/ea games/mohaa/main/maps/
rshcmd:
entitydir: code/
modelmask: *.tik
moddir: main

Ending up looking like:

It is very important that you use the correct basepath, as this is where it loads the textures from. Click "OK" and you're good to go.

To change your MOHRadiant preferences click "Edit" on the toolbar and go to "Preferences."
Although you can set it up however you want, I suggest it is set up to match mine so there is less confusion in my tutorials.
However, you are free to set it up whatever way makes you comfortable.

On to MBuilder.

Unlike MOHRadiant, you do not have to install MBuilder.
All you have to do is, when you want to compile a map, run MBuilder.exe.
Leave the BSP, VIS, and LIGHT options alone.
The game directory is simply where you installed MOH: AA, by default it would be c:/program filesEA GamesMOHAA
The compiler directory is where you have installed MOHRadiant. Once again by default, c:/program filesMOHAATools
Map source directory is where your maps are saved. This is usually c:/program filesEA GamesMOHAAmainmaps but can be different.

When you are ready to compile your map, you would run MBuilder and select it from the list of .map files and click "Build Map!"
A DOS prompt will run. You don't have to watch it, but if your map doesn't work it may contain lines that will tell you what the problem is (such as a map leaking).

Pakscape

Most of the modders/skinners will have this, so you can just skip this section if you know how to use it.
For those of you who don't, I'll just go over what it does and how you can use it.

All files, such as textures, skins, models, maps, sounds, etc. are kept in .pk3 files.
MOH: AA loads these .pk3 files on startup (if you haven't noticed).
This allows for easy customization in the game.
That's really all needed to know at this point.
As I get to building the first room, I will discuss how to use Pakscape to get your map in the game.

Congratulations! You have successfully installed MOHRadiant, MBuilder, and Pakscape... Hopefully. If you have any trouble I suggest you go here:
Nemesis Tutorials
The tutorials there are very good and what I used to learn how to map. If you have any questions you can e-mail me at:
selzi@acidbath.org
Once you're all set, it's on to creating your first map! It's fun, trust me!