I just explained this to someone too. Maybe this will clear it up a bit also:
Planets represent a part of your personality/psyche (ie. Moon = emotions, Venus = relationships, etc.)
The signs that your planets are in indicate why and how you demonstrate that planet (to understand this you must know the different characteristics of the signs)
And finally, the houses represent the areas of your life. Ie, Sixth House is the house of service (work) and also covers health.
You might get different interpretations from different people or different places on the net.
I got mine from a book I am currently reading called the InnerSky which was recommended to me by someone on here. It really helped out to understand the basic structure of a natal chart. It goes over the chart wheel, the planets, the signs and the houses and the aspects. I am currently learning how to interpret the aspects. It is very interesting.