Texture swapping

When rendering with multiple textures, what's the best way to swap them. I have 3 textures used for landscape and 1 for objects. The 3 textures for landscape are loaded into 0,1,2 and the landscape drawn using 4 stages. Then to draw the objects, I change texture 0 to the object texture and disable the texture stages and render the objects. In the next render pass, I have to reset texture 0 to the first landscape texture (1 and 2 are left intact from the first pass). Is this the right way to do it? If I have 4 object textures, do I just change texture 0 to each of the object textures and render? If you do SetTexture(0, ) is that actually loading the texture onto the video card? Or is it already on the card when you do LoadTextureFromFile (or whatever the method is). Thanks