Well, since you are new and undoubtedly still have a lot as far as your style to develop, (if you really get into bowling I would strongly recommend getting a little coaching) I would go for a medium strength ball with a moderate strength cover until you know what will work for you. I would suggest either a Spit/Sure Fire, T-Road Solid, or Thunderstruck Solid, depending on how aggressive you want your ball to be. (T-Road should be strongest, then Sure Fire, and finally the Thunderstruck, but surface adjustments would make the Sure Fire slightly stronger) Unfortunately, the Sure Fire is not out yet, so you will have to wait for that. I, personally, would recommend the Thunderstruck Solid. (not to be confused with the T-Road Solid)
However, I would note that finding a good driller is just as important as selecting the right ball. You don't want a layout that is overly aggressive or too tame, as it may cause the ball not to react as desired. Ask around and see if you can find a good driller, and make sure to explain the reaction you are looking for and your circumstances (i.e. style and that you're a new bowler) to get the best results. If possible, see if they can even watch you a few games to get a more accurate read on how you bowl.
Good luck, I hope this helped.
Edited on 8/15/2007 3:45 PM