Got some new things for the Dollhouse I'm making

Firstly, I have assembled a nice bedroom cabinet:

Above: The inside
Above. My general problem when I made this was that the doors wouldn't close the way it should. I think I made the spaces too tight on this one.

Above: Right side up.
Above: Wrong side up hehe.

I realized that maybe I should get a varnish and cover the necessary wooden furnitures with it to add gloss and to protect themselves from dust. Hmm, should I use brush with it? Or spray it...? *mumble mumble*