There are a lot of resources available, both on and off of T3A, that can help wit any aspect of Battle for Middle Earth's Graphics. This post contains a list that is by no-means exhaustive, breaking down the tutorials by category for easy reference.
I will add new tutorials that appear on our site periodically, as well as any I find offsite. If there's any you would like to see here, post them and I'll check them out.
The shape and form of an object
Beginner Modeling Tutorial
Learn how to import EA's ingame models and edit them - here, FlameGuard will show you how to remove Aragorn's cloak.
Editing a Model
Beginner modeling tutorial - learn how to add a bow to a Rohan Peasant and export it.
Cutting Parts or Weapons from Models
This tutorial will teach you have to modify the weapons an existing unit has - say you want to give a Gondor Soldier an Axe.
Scratch Modeling a Human
This tutorial will take you through one method to create a human model (except the head) from scratch.
Scratch modeling a head
For the more advanced modeler, cahik shows his method of constructing a detailed head.
Making them move
Binding Human Models
Rob38's Ultimate Guide - the definitive resource for the Haldir skeleton, and pretty much any human model. Shows how to set up a skeleton, use space warps, and rig every part of the model.
Basic Binding on Horses
Quick and easy way of binding a troublesome kind of model: horses.
Basic Texture Tutorials
Giving a model a 'skin'
Creating Orc Armour
A technique tutorial showing how to draw a set of Orc plate armour.
A technique tutorial that unifies the texturing, modeling and unwrapping of a Numenorian Shield.
Similar to the above, an older technique tutorial that walks you through the texturing of a Gondorian shield.
Learn how to draw some really basic rough cloth pieces, like a cloak.
Learn a technique for creating large sheets of scale-mail (can be applied to chainmail too).
Learn some basic ideas and methods that could help you draw leather armour for your models.
Texturing the Golasgil Household Knights
A long tutorial detailing the entire procedure of texturing a unit. Contains methods for cloth, chainmail, plate armour and anything you'd find on a medieval soldier.
Specialized Texture Tutorials
Doing fancy things with textures
House Colour Textures
This tutorial will teach you how to add team colour textures to a model.
Creating Basic Normal Maps
Learn how to add depth to your textures with normal maps
Applying Normal Maps
Learn how to apply a normal map to a model.
W3D Materials and Settings
Transparency, forged blades and the like
Forged Blades and Fire Arrows
If you're looking to understand how to make your Forged Blades and Fire Arrows look like EA's, all the settings are here.
Vertex Painting in Gmax/RenX
Sometimes you need to work with this powerful transparency/lighting tool; this tutorial tells you how
How to set up and use the tools of the trade
How to Set up and Install W3D Importer
To import models from the game into RenX or 3DS Max, you'll need to read this.
Importing and Exporting .obj files from RenX
To use other modeling apps like blender with BFME, you'll need to import models - this show how.
How to use W3D Viewer
How to use the handy program EA provides to view models.
I haven't added 2D art, animations or hex-editing yet, but those will be forthcoming once I read + categorize them.