Find the plan of the building on the blueprint. For multistory buildings, there are many plans, so find the main or bottom floor. The plan will be annotated with room names and numbers, dimensions, notes, section cuts and other call-out symbols. The section cuts and call outs will have a circle with a line dividing it in half. In the top of the circle there will be a number or letter; in the bottom there will be a number or combination of letters and numbers. These annotated circles refer to other drawings that provide more information for the plan.
Read the annotated circle associated with the section cut or call out. The top letter or number is the drawing number, and the bottom series of letters and numbers is the drawing page. For example, a circle with "5" on the top and "A201" on the bottom refers to "Drawing 5 on Page A201" in the blueprints. So, the annotated circle works like the index in a book.
Turn to the page and drawing referenced in the annotated circle. If there is only one page of drawings, the circle might not have the bottom number. Like the plan, the referenced drawing will have call outs and other annotations to fully describe the building. Use the call outs to navigate through your blueprints.