Hello Gizmo,
First, you will probably get more and better responses to this in the GECK section, as that is where modders usually consult with other modders.
Second, animated objects are the same in fallout 3 as they were in oblivion. The only differences are that the files have a slightly different header (which the nifscripts take into account) and constraints use a different setup (you only need to use constraints for havok-capable meshes like creatures).
Now here are some useful links:
http://cs.elderscrolls.com/constwiki/index.php/Category:Animation_Tutorials <-Animation section on the oblivion cs wiki. You should read the basic animation tutorial as it profides good explanations on what the different blocks in animated .nifs do.
http://cs.elderscrolls.com/constwiki/index.php/NifSkope_Alchemy <-This is a basic guide to using nifskope. You will have to do some editing in nifskope after exporting.
Unfortunately, there isn't a simple tutorial focused on creating animated objects that I am aware of. However, the process can be broken down into steps requiring a specific knowledge base, and there are tutorials aimed toward those goals.
In order to create animated static (not npcs or creatures) objects you are going to have to:
1. Create a mesh and texture a mesh
2. Create an armature
3. Rig your mesh to the armature
4. Create animations
5. Splice it all together in nifskope
6. Possibly set up an activation script in the GECK to call the correct animations on your object.
Which of these steps have you done before and which do you need help with?
Also, if anyone knows of specific tutorials for animated objects, please post them.