We basically take complicated CAD drawings from architects and turn them into simple, easy to understand maps. We usually ask if we can take a walk around the building before we start to help orientate ourselves and take a few pictures. The images can be as complicated or as simple as you like, you can keep it just as basic floors and walls or include furniture and people. You can have these printed out in posters or flyers, have PDF versions on your website could even make them interactive.
These maps come in very handy for visitors, sending them the PDF of the building layout before they arrive can be invaluable. Appearing open and useful to customers can have very positive effects, it keeps them engaged and avoids confusion.