This is a porsche forum... granted there are surfers here... myself included... but I recommend you post your question here:
http://jamlongboarding.com/forums/view_forum.php?id=1
There you will find some very well-informed life long waterman that'll help you. My handle over there is swellsearcher. =)
As far as what I can do to help you answer your question...
First we need information from you...
-How old are you?
-How much do you weight?
-Where do you intend on surfing? beaches, rock bottom breaks?
Answer those questions and I can give you a recommendation...
For these guys to be saying "more rocker with softer rails" or "no rocker with harder rails" is not sounds advice.
An old school board, that is flat, thick and has 50/50 rails is not going to be an easy board to learn on. No rocker means 'angling in' on take-off. An old school board will usually have a sinle fin, which means turning from the tail. Not easy things to have to learn to do...
On the other spectrum, a short board with rocker, hard rails and a thruster fin setup isn't going to be ideal either. There's little stability when compared to a "longboard". The board won't glide, it'll sink, unless you pump and turn it. Hard as hell to paddle and even sit on.
By the way, if you're scratching your head thinking, "what the hell is rocker?" Check out the Harbour surfboards website. IIRC, there's a surf dictionary section that is very comprehensive.
Ok, I'm on a roll, he is some very general advice. Look for a used, but surfable condition mid length hybrid / funboard.
Used: Dont spend more than $200-$250 for your first entry board. Being that you won't know if you'll want to shortboard or longboard in the future.
Mid length: 7'6 - 8'6
Hybrid / funboard: Will have rocker, pulled in nose, thickness through the middle section of the board, harder rails, and a 2+1 or thruster fin setup.
Here are a couple examples:
Becker hybrid: leaning toward more aggresive from the middle...
http://beckersurf.com/ProductDetails.asp?product_id=5590&product_subgroup_id=154
Becker LC-3: I'd say this board is pretty smack dab in the middle of what you'll see in the water.
http://beckersurf.com/ProductDetails.asp?product_id=5593&product_subgroup_id=154
See you over on longboard.net!