I have been developing my knowledge and understanding of front and rear focal planes and have found various charts that one can use, but I came across this app which I think is very handy as it provides a visual interpretation.
Lens•Lab is a virtual lens simulation tool for photographers of all skill levels. It graphically illustrates how depth of field and field of view relate to your SLR camera and lenses.
If you own a Mac you can download it for free. The app is available for the iPad, iPhone and is also available for android as well.
I just thought other people might be interested!