texture depth help

i added 3 textures to a plane,the first one is the diffuse map, the second is a normal map of the same texture, the third one is a spec map of the same texture, each one of the textures from the slots has it’s own settings on the influence panel, the diffuse texture is mapped to color on the influence panel, the normal map texture has the col disabled but enabled the Nor button and enabled the Normal map button from the “image sampling” panel, and the spec texture is mapped to spec intensity, now i’m wondering what next ? what kind of textures i can add to the fourth slot now and mapped to what in the influence panel, plz help ?
this is the result so far:

Well, it looks like your specularity is a bit high overall for that material, but unless you want more textures theres no reason to add more textures. Actually what you have done could be done in one texture slot since you only have one texture. But if you wanted to say, add a grunge texture, it might make sense to put it on another texture layer since you wouldn’t want to add it to your other diffuse texture.

ok i added now only one texture in the first slot and mapping it to Color, Normal, and spec intensity, but the result is not so good as the first image.
and by the way in the “image sampling” panel the Normal map is off for the normal map texture