gen questions

i've had this mac since february and i'm still learning all of the neat little functions.
i'll probably always be learning something new..
anyway..
1. i was going through the system preferences and i can't seem to figure out how to RENAME my computer

2. when i'm in finder i don't see my mac drive. i think i may have disabled it from showing up..because i see my ex hd. how can i get it to come back in the finder window permanently..so that it is listed under my devices?

3. when in finder, under devices..there is "idisk"
what is this?
sometimes i click on it on accident and always get an error that it's not available.

1) If your talking about your network name, just go under Sharing in System Preferences.

2) With System Preferences open, go up to the Menu Bar and click on Finder > Preferences...it's probably unchecked under there somewhere?

3) With System Preferences open, go up to the Menu Bar and click on Finder > Preferences...then choose the Sidebar tab and uncheck "iDisk"

1) If you mean naming the hd icon, all you have to do is click on the name once, wait briefly, click on the name once again, the name (probably Macintosh HD) will be highlighted... type the name you want.

3) iDisk is the online storage Apple offers through .mac (ok, yea... I know... it's now called mobileme). You have direct access to your online drive through the iDisk icon.