If you are looking for a book about making minis that has useful diagrams, scale patterns and a range of complete projects, then Making Miniatures in 1:12 Scale by Venus and Martin Dodge could be very helpful. It caters for miniaturists who are just beginning in the hobby as well as to the more experienced.
The projects provide all you need to know to make the full settings, from the container down to the smallest accessory. For example, the chapter on making a potting shed begins with constructing the shed and goes on to show how to make the little things to go inside it, such as a broom and a ladder.
This book starts with chapters on how to make room boxes out of wood as well as general advice on what hand tools and power tools are needed.
If you don't want to make a construction out of wood, then there are chapters on making 'shoebox rooms' out of thick cardboard.
You can choose to make scenes as varied as a mermaid in a real goldfish bowl, a market stall, a secret garden, a farmhouse kitchen, a lady's bedroom or a fashion emporium.
All the projects can be stand-alone settings or the ideas could be incorporated into your dolls house.
The authors have many years experience making dolls houses and miniatures and have written other useful books on the subject.