Get started by choosing the place where you want to install the book case. Then with the help measuring tape, take and record the length, width and height of the area where the bookcase can be best installed.
After taking the measurements, brainstorm a rough map of your bookcase on a piece of paper. This may include the length, height and width of the shelves, the points where you will nail the side boards and if required the back boards. Then slowly and gradually refine this rough map into a clear and well planned architecture with proper space allotted for every shelf.
Now that you have got all the measurements and an architecture of your bookcase, its time to get your wooden boards cut into shelves, panel strips, back panels and panels for sideways and the doors. You may consult your carpenter for this if you cannot cut these boards on your own by giving him all the measurements and plan that you have just noted down.
Also do not forget to get the handle and lock installed on the doors of the bookcase.
After having the wooden boards cut into all the desired shapes and lengths, assemble them by nailing the back panel on the base panel. Afterwards, nail the side panels and then the roof panel. Continue down the shelves in the same manner until all the panels are assembled into one unit.
Installing the Door
Make sure that you have got the door hinges of suitable size keeping in view the breadth of the bookcase side panels. Mark the points with pencil where the hinges will be installed. Now make holes with the drill machine and nail the hinges. As you are done installing the hinges from one side, its time to attach the other side with the door.
So for the measurement sake just bring the door near the bookcase and roughly fit it with the bookcase to identify the points on the door that comes parallel to the hinges installed. Mark them. Now making holes with the help of the drill machine nail and install the other side of the hinges into the door. Now repeat this process to install the door on the other side.
Your door bookcase is ready so arrange your books in your closet and don't forget to close the door.