I'm only into my second year of hunting. Partridge, duck, goose. I bought a 28" 870 - bare-bones, base-model that I could get dirty and not cry about scratching. I shoot steel through it. Don't even bother changing it up from duck to partridge, save for the choke. Works great. It was better used for walking while hunting, where you have a chance for a second shot. However, I find myself now riding a quad (actually just bought one). Last year, in my buddy's side-by-side, I found I was having equal success with just firing a single shot (since you can't carry a loaded shotgun on a motorized vehicle). I'd just pop the shell in the ejector, slam it forward, and pow - bird in the bag. I never really had to take a second shot when it comes to partridge.
My buddy uses that Norinco 12" coach gun double-barrel. The "Outlaw". I've got one, too. For partridge, it's great. Small, easy to transport, easy to get in and out of the Wildcat with it, perfect for partridge. Obviously not so good for duck.
Mrs. Cannon prefers my Benelli M4 Super-90. Yes, she shoots partridge with it. I've never tried duck (I have a ton of chokes for it), but we do use it for card shooting and actually sometimes win with it. However, at $2200 I almost had a stroke when she tripped out walking this year and dropped it into a muddy puddle during the last week for small game. Not to mention, it's actually heavier than my 870. Not such a big issue driving, but walking it makes a difference.
By new to shooting do you mean new to hunting, as well? Honestly, you may want to just start out with a $400 870. There's a million accessories out there for them. I find I can pump mine fast enough to get a spooked duck on the third shot - I've done it. It's a faithful workhorse. Nothing fancy, and you can get different barrels depending on your applications.
I also like the side x side. I'm going to try that this year, too. For me, I can't see why a single-shot wouldn't work. You generally don't need a follow-up shot for partridge.
I bought my buddy a Remington 870 synthetic pump hunting kit for his birthday. It was in the area of $500-$600. Came with an 870 with synthetic forend and stock, a 26 or 28" barrel (I can't remember), choke, and a shorter rifled barrel for deer, plus fibre-optic magnetic sights. You may want to look for something like that.
I see prices have gone up a bit this year, but here's an example. I bought his from Colby.
http://www.thegunroom.ca/index.php?route=product/product&path=83_102_117&product_id=630
And here it is:
http://www.thegunroom.ca/index.php?route=product/product&path=83_102_117&product_id=631
Just my two cents, anyways.
Cannon