The materials are designed to be as user friendly as possible - so far they only use standard Blender settings; no plugins yet. To get the best use out of the reflective materials, you may want to read the information regarding environment maps on the tutorials page.

Read a tutorial on using the Blender Material Library here.

Nothing in the world is perfect and this library is no exception. How good a particular material will look in your scene will depend as much upon the lighting as the material settings themselves. The shape and size of the model that you are texturing will play a big part too. You will almost certainly need to tweak settings to get exactly the 'look' that you are after, so think of the library as a good starting point rather than an instant source of 'ready to go' materials.

Hopefully the materials provided to start this library will inspire you to make more effective ones of your own. If you have a new material that you're willing to share with the Blender community (or a substantially better version of something that is already in the library), mail me a simple zipped .blend containing a single primitive mapped with your material and I will add it to the library. (I'll try and include everything that I'm sent, but please avoid just tweaking something and then sending it back - there are only so many versions of any one material that people will want to sort through).