I tried doing the adjustments myself as I noticed the chains are getting a bit noisy after hitting a couple of trails. I think I made it worst I tried following some youtube vids but can't get it right.
The bike is about 2 weeks old. How soon can I take it to the LBS for tune up? Will the tuneup include checking the derailleurs and making sure its quite or should I need to tell the LBS about it?
Here is a site that I like a whole lot: http://bicycletutor.com/. The guy behind the site does an excellent job on his videos.
If the bike is new and you've had it for two weeks, it's probably worth bringing it back to the shop for some adjustments. It is common for a new bike to need some adjustment soon after someone begins riding it regularly.
If you go to the shop, tell them what you did. You want to help them solve the problem for you. The more information you can give them, the easier their job is. Don't hide information from them.