First of all I'm a blender newbie who would like to animate some models hosted here :P.

There is a nice repository of motion capture data (2500 animations) : https://sites.google.com/a/cgspeed.com/cgspeed/motion-capture

USAGE RIGHTS:

CMU places no restrictions on the use of the original dataset, and I
(Bruce) place no additional restrictions on the use of this particular
BVH conversion.

These mocaps can be imported as BVH into blender. Then you just have to link the armature to the mesh. here is a video tutorial explaining this : http://www.youtube.com/watch?v=3YY12TkXGqc&feature=related.

This work quite well if the rest position of the armature matches the one of the mesh, which occurs rarely in practice ... I tried to import a BVH with the ogre model here : while the upper part of the body was well animated, there were problems with legs.

So now I see 2 solutions : modify the mesh so that its T pose matches the one of the BVH file, or create an armature pose that matches the one of the mesh and attach the mesh to the armature in this pose. While the second solution seems easier, the first one would allow to use nearly all the BVH files with the model once its bind pose is modified.