Starting the journey:

First looking for hints, searching macro-photography on the internet. As usual first to pop up is wikipedia, so I will start here.

Depth of field is extremely small when focusing on close objects; a small aperture (high f-number) is often required to ensure sufficient depth of field.
Limited depth of field is an important consideration in macro photography. This makes it essential to focus critically on the most important part of the subject, as elements that are even a millimetre closer or farther from the focal plane might be noticeably blurred.
Lighting
The problem of sufficiently and evenly lighting the subject can be difficult to overcome. Some cameras can focus on subjects so close that they touch the front of the lens. It is impossible to place a light between the camera and a subject that close, making extreme close-up photography impractical. A normal-focal-length macro lens (50 mm on a 35 mm camera) can focus so close that lighting remains difficult.
http://en.wikipedia.org/wiki/Macro_photography