User Permission Issues

As you can tell from my question it's needless to say I'm a linux newbie... :)

First off, I read one of Ubuntu's advantages from other distros would be that you could manage permissions on your own account instead of logging on as root (sort of an administrator account if I got that right). Am I right?

If so, I wonder I might have set up my account incorrectly for the system doesn't allow me to access certain folders such as "lost+found" and "root" for instance. Thus I would like to know how I can set up administrator-like privileges as I am the only user on my computer.

If not, I would like to know how to log on as admin (root?) in order to access and do some restricted stuff.

Secondly, I'll take this opportunity to report some strange thing that is happening which I'm not sure whether it's a bug or it may be somehow related to my permission issues. Here it goes:

Sometimes I start my computer and Ubuntu (btw I'm running 10.04 LTS Lucid Lynx) just don't recognize my cd/dvd-rom drive (LG secur disc; super multi model) and my sound hardware (onboard ASUS M4A78). It just doesn't recognize there's a cd or dvd inside on the desktop icon and when i try to open it anyway I got the same denial of access supposedly due to permission issues.

Besides, when I try to shutdown or restart the system, it just jumps to the log on/off screen instead. As if I had logged off somehow... So I'm forced to shutdown or restart by holding the power on/off button or pressing the restart button on my hardware, respectively.

Finally, I would like to emphasize that such "bug" only happens when the system starts and don't recognize the mentioned hardware. This morning, for instance, the system just started up fine and so I'm using my dvd drive and my sound card properly. Also I'll surely have no problem shutting down or restarting the system later on.

Thanks in advance,