The furniture is self explanatory. All you have to do is look at the pictures in the instructions and you can build them.
I think that the furniture for this dollhouse is great. It's laser cut so you get the nice and neat edges and they finish quite beautifully.
You can glue them in place or leave them movable. I have staged them in the dollhouse so you can see how they would fit.
If you want to make the first floor shelving a built in, you can always glue it in place before you wallpaper so you can stain or paint the back wall of the dollhouse to match it, giving the illusion that the shelving has a backing. Then you can apply your wallpaper around it.
You can visit this dollhouse gallery here.