Normal Maps on Interiors

Okay, I'm most definitely not a seasoned developer for TGEA, but I want to make use of normal maps on interiors and, eventually, models. However, I have no idea where to start. I mean, I can make an interior, and I can make a normal map, but I don't know how to put the two together. I really haven't had any experience working with TGEA's differences in the rendering (I assume preparing the interior remains about the same, but...)

So if there are any extra steps I need to take in the preparation, please let me know. In fact, most handy would be just a step by step explanation of how to do it, or a tutorial that does that. I thank you in advance for any help, and look forward to being able to get my ideas out into the game!