Having said that, you may need to create your own materials to apply to each part of the object, if you don't like the materials that come with ArchiCAD. In this case you will have to use the Option>Materials command to create your own. This is a broad topic - probably best covered in person!
(Sorry - you know how much I'd like to visit Bermuda - and work would be a good excuse!). Just make sure that any texture you try it apply to a material is filed within a loaded library!
Good luck.
Cheers,
Link.