With Assimp you load an aiScene which contains the list of meshes contained in the the model (I guess you already use that).
In addition you have a pointer to the rootNode (aiScene->mRootNode). Nodes (aiNode) give you the tree hierarchy of the differents elements of the scene, contains transforms, can be bones or contain meshes. Animation data points to nodes (in aiNodeAnim, you have the node name), changing the transform of a node over time.
So to handle animation properly, you have to handle the node structure, particulary if you plan to use skinning.
I hope this helps.
Edited by DTR666, 18 February 2014 - 02:25 AM.