each planet governes different things.
mars = male energy, proactive energy, beginnings, assertiveness
venus = feminine energy, nutrturance, romantic love etc.
mercury = mental energy, communications
jupiter = expansion, growth, luck
saturn = contraction, discipline, order.
neptune = subconscious watery idealist creative forces
and so on.

so which planet is in which sign shows how the energy of that planet is expressed in your personality.

sun sign is your basic personality.

the moon sign is your internal, emotional personality. it comes into play in close interpersonal relationships.

the rising sign is the face you show the world, its the mask you wear in order to interact with society. it is said that scorpio rising is the most powerful of all rising signs.

here is an excellent overview of scorpio rising. you would be the first decan.

http://www.elbertwade.com/page105.html