Rigging a CAT rig

As I will be using 3Ds Max for animating the character, I went to Youtube, then to the 3D Studio channel. They have a whole heap of tutorials in their library. I will be using THIS video to help me with my Rigging.
One change I will be making is by adding an extra "bone" to the forearm. This was a suggestion by my animation tutor. It stops the entire forearm from twisting when you rotate the wrist. Try rotating your wrist. See how very little of the forearm near the elbow twists? You could even argue that it is simply a muscle bulge making that area move. It's because by twisting your wrist, your Ulna and Radius are moving in your arm, along with the Carpus (wrist).

This image, from Doctor Bruce McFarlane's BLOG, ITTCS, shows how the Ulna (shown in RED) and the Radius bones move when the wrist rotates.

I will update this post with my CAT rigging attempt from following the 3D Studio tutorial, with the adjustment I mentioned.

UPDATE:
I have rigged and partially skinned a model. I have not altered the Envelopes, so there is a lot of strange action going on, like stretching and the thighs morph rather bizarrely.

I have also documented my process with a series of Screenshots.

Firstly I opened the Mesh file up. Spiderman is stood in a Tpose

Selecting the Mesh, I pressed Alt + X to enable X-ray mode. I froze the mesh at this point for ease of rigging.

I created a Base Human CAT rig from the Helpers Section

In side view, aligned the rig with the meshes waist.

CATUnits Ratio alters the height of the rig. I renamed the rig Spiderman_ so all of the components would be names, for example, Spiderman_LeftFoot

I resized the waist to fill out the mesh and help aligning the legs. I also rotated it slightly. Using the Copy and Paste Mirror buttons, I placed the Legs. I also added an extra Bone to the feet. As the model is wearing boots, I don't need to make all five toes.

I align the spine and neck to follow shape of the mesh. Moving the ribcage resizes the spine bones automatically, as does the head with the neck bones.

I resize the ribcage to better fill out the mesh. This will help when it comes to setting the enveloping areas of skinning.

Aligning the arms, I moved the collarbone slightly, then began setting the arms. I added the five digits to the hand and resized them using my own hand for reference, lining up the knuckles. I added an extra section on the forearm to represent the Ulna and Radius bones.

Copy and Paste Mirror to set the other arm.

This is how the mesh and model look when combined. I select the mesh, then apply a Skin Modifier.

I use the Spiderman_Pelvis selection as my bones, then Ctrl+C to select all of the Children files within. This contains all of the bones I need, leaving out the Footpads and the main selector (the triangle with the arrow).
As the mesh is separated for the neck, head and the eyes, I do the same with them. Without this, those sections will not be animated.

As noted above, there are lots of things to be corrected. I have just uploaded this to show my working so far. My next steps will be to adjust the enveloping sections to correct the stretching.

I used the Motion section to animate Spiderman with a Sneaking animation. I have hidden the rig contained within.