problem with textures

I figured out my old problem and it is working great. But now I went to add textures and am having another problem. I load a texture in with D3DXCreateTextureFromFile. Then use g_pD3DDEVICE->SetTexture. defined the vertex data and everything. I create a simple imgae in paint and run the program. The texture loads in and is displayed but it only shows the base color? So like i make the whole image red and put blue spots on it but it only displays the red. Why is this I can show some code if it would help. Also I am sure it is not the video card drivers or anything like that because I have compiled other samples and they work fine. The main thing I can think of is that I don''t really define u and v cordinantes. but I thought it would default to 0,0 where do i define these anyway? The only thing that defines man from animal is our knowledge of computer programming.