
The following examples should give you an idea of which apertures create which kind of focus and depth of field effects. In each photo, the aperture was adjusted by 1-2 'stops', and the shutter speed adjusted accordingly to create the same exposure.

f3.5 = wide aperture = shallow depth of field (less in focus)
Notice that the flowers and the leaves around them are the only thing in sharp focus.

f5.6 = medium to wide aperture = shallow- medium depth of field

f8 = medium aperture = medium depth of field

f11 = medium aperture = medium depth of field
Notice that the bin is starting to come into focus now.

f16 = medium to narrow aperture = medium to deep depth of field

f22 = narrow aperture = deep depth of field (more in focus)
Notice that the background of the kerb and maroon car is now is reasonable focus, and the flowers and leaves are also still in sharp focus.