Bicycle Mechanics - Bike chain/rear derailleur is making too much noise!

I just bought a bike on www.bikesdirect.com. It's a 24-speed Windsor Wellington 3.0 road cycle. It has a Shimano Sora 8 speed rear derailleur. On my first ride, it roke ok, but the rear derailleur and chain made too much noise and it felt like it didn't feel smooth. I'm not sure if this is a cheap bike, but I paid $400. I added lube to the chain and went online to teach myself how to make the adjustments to the rear derailleur. Not sure if I did it right, but I just followed the directions. I took it afterwards and found that the middle gears tended to ride smoothly, but the higher and lower ones did not. They were noisy and sounded like there was some friction there. Should i just take it to the LBS? Or should I try to make the adjustments again? Or should I just return it and buy a $400 bike from my LBS?

Sounds like an adjustment problem. There are excellent instructions on how to set up and align the DR on the Park Tool site among others.

First and easiest way to check without taking anything apart is to shift to the highest (smallest) cog and check the cable tension. There should be almost no slack in the cable, but it shouldn't be overly tight either.
If there is any slack, use the adjuster to snug it up.
While you're back there, eyeball the DR' arm, the hanger, etc and make sure it's dead straight. It's easy for a slightly bent hanger to cause similar problems.

Are you getting noise with the small ring & small cogs OR the large ring and large cogs? If so, that's called cross chaining and it's a NO NO.
Small ring- gears 1-6.
Large ring- gears 3-8.
(or so)

I've seen some bikes come with the chain wrapped around the OUTSIDE of the rear-derailleur cage instead of around the pulleys...