For children it is better to make a ladder with a handrail and it is correct to calculate the step width that it was convenient and safe to child to get on the second floor.
The size of a berth of a children's bed is defined by standard dimensions of mattresses. As a rule, it is 16070 cm. There are transforming beds providing lengthening of a berth in process of growth of the child.
Council. If you decided to make a bed of a chipboard, collect it on confirmation candidates — euroscrews. They hold a chipboard much more strongly. Laths under a mattress and crossbeams of a ladder have to be made of a tree. It is not recommended to do boxes on the top circle because of the big weight of a chipboard, it will weight a design.
When all materials and tools are collected, get to work.
If independent creation of the drawing — too difficult process for you, use ready schemes.
Council. At production of a bunk bed from a chipboard do sidewalls of an integral leaf. Any cuts on them weaken a design.