I done my little set of tasks.
Its all very simple.
I found jupming in and trying to build something big, was not working for me at all.
My program can load D3D into a window or into fullscreen - for some reason the sprites are not shown in full screen. I suspect I might see them if I scrolled my screen up with the controls. I'll leave this until I've done some big tiling.

First program puts a tile at the correct place in the top left hand corner of the window. Textured from a 256x256 bitmap taking out a 32x32 chunk, to coloured the tile grass.
Then the second program used the same vertex buffer but changed the texture and put that next to it.

So I now have a nice piece of grass followed by a gray tile that looks nothing like a road.

Unfortunately to do this I have to lock and unlock the vertex buffer. I hear this is expensive but unless I'm missing some command I don't know how else to do it. Unless I have different vertex buffers for models that share everything bar UV co-ords.