Having a rooted nook means you can do more with it. Rooting it does not get rid of anything you already have. That said though, you will lose your warranty.
If you want to go through with rooting your nook, find out your nook's serial number. If it starts 1002 and below, then you can use the old method. If it is 1003, like mine, rooting it will be more difficult, complicated and risky, but still very doable.
1002 tutorial:
http://nookdevs.com/Softroot
(Note: There is a 2.5 rooted firmware now, which is the 1.5 official firmware for rooted nooks)
1003 rooting tutorials:
First, you have to downgrade from official 1.5.0:
http://nookdevs.com/User_talk:Naerymdan
With Router Method:
http://nookdevs.com/Applying_With_Details
No Router Method:
http://nookdevs.com/Rooting_New_Hardware_No_Router
Updating to 1.5.0 after rooting:
(Scroll down to "Update to 1.5")
http://nookdevs.com/User_talk:Naerymdan