Texture the inside of a model using UV Texturing

I am trying to create an indoor complex for a game I am working on, however, when I try to use the conventional UV texturing method, it only textures the outside (or at least as far as I can tell). Does anyone know how to do this?

Thank you in advanced.

Flip the face normals. Select the faces (W / flip normals) or ‘recalculate them inside’ Shift+Ctrl+N

Thank you very much

When would I do this during the texturing process?

Before or after makes no difference. The face still gets textured, it will just change the side the texture will show up.

Check which way the polygon is facing. In Edit mode select faces you want to check, in “Mesh Tools More” tab select button “Draw Normals.” The pointing tick marks will show up on faces. And the texture will be drawn on the tick mark side. If you find the tick mark on wrong side just do “Flip Normals.”