Does it have the potential to brick the device?
Yes, it is possible to brick your phone, but should be very unlikely. Usually there is a way out of even what seems to be a brick.
If you do not know what you are doing and want to use the ADB method (entering shell commands manually) to root your phone, then be sure to follow all of the directions exactly as listed. If you somehow brick your phone, then it does not matter how good your phone insurance is with your cell provider; if they find out you rooted or attempted to, they will not fix it.
If you do somehow brick your phone, then do not panic. Try these things:
- Post a thread to where you downloaded the root program or where the root method was posted.
- Post to XDA under their questions and answers section.
- Search the web. Someone else has probably had the same problem as you.
It is quite possible to unbrick your phone, but it will take some time and patience to sort it out.
Will it void my warranty?
Yes. But in most cases you can restore your phone to a condition that they'll never know that you rooted your phone. And sometimes they do not even check to see if you rooted your phone when you return it.
Will I stop getting updates?
Yes and no. If you flash a rom, yes. But most likely that rom has constant updates (such as CyanogenMod). Also if you root and keep stock rom, you will still get OTA update notifications (but running an update will un-root your phone).
Anything else I should be aware of?
May the force be with you. No, really, it's a relatively painless process with a lot of these "easy one touch (un)root tools" and even then there is a plethora of guides and help from XDA to guide you and troubleshoot any problems you might have. But if you are happy with your phone just the way it is, then don't root.