PoserPro 2010 (please note the actual name) does have drag and drop feature for textures.  The response LaurieA posted is correct, most textures for M3/V3 are in the form of MAT Pose files found under the Pose Category of the library.  In rare instances, MC6 files might be the only convention to apply textures.  Direct application will need to be performed in the Material Room.