hey there diverbug.....
I am also relatively new and started just like you, also asked for some advice..well I can tell you I have had some help from some guys here on the site and went diving with a experienced guy for a couple of times.
I think, you have been diving, scuba, that the most important thing is to get in shape, work on your bottom time, do some static breathhold training, cardio etc...,
(I do scuba as well and can tell you that most of them, with a lot of experience etc, do not make them great" spearfishers")
Work on your diving skills, buy a few DVD's and look how these guys use their fins, how they equalize, and go down...., how they use their guns..
Go diving without the gun, see how deep you can go, without any problems, how long you can stay under etc....
Read, on this site for example, about the way fish react, were you can find them, etc...
Get yourself some good equipment, a good gun, good suit and mask...try to figure out how much weight you need....
( I crashed on the bottom once with to much weight 20 meters deep
)
And very important, learn and read about safety...
Anyways....started seriously 3 months ago, now I Icome home with my dinner, ok...I live a couple of minutes walking from the sea, and go dive 4/5 times a week....still much to learn but I am happy guy....
Let me know how you are doing, good luck....you are about to start with the coolest thing....
Greetings Mike