The bootloader (aka HBOOT) is bit like the BIOS of your computer -- it is a very basic UI with limited functionality, but it is VERY important because as long as the bootloader is locked (as it is by default) you cannot flash a custom recovery (or so is my understanding)...and if you can't install a custom recovery, you can't install ROMs. In most cases, when people refer to "rooting" a phone, this includes unlocking the bootloader as well, even though that's really a separate thing from gaining root access to the OS. Since you state you're familiar with Linux, then you should understand what root is...it's like the "administrator" account in windows -- it has full access to the system. The "recovery" partition I compare to the pre-install environment of a Windows OS (like when you boot from a Windows CD, or a linux distro like Ubunto for that matter). Once booted into recovery, you can make changes to the system files, format drives, and install new OS to the phone. All of the procedures found in the stickies on this forum will complete all 3 of these steps...once finished, your TBolt will have an unlocked bootloader, a custom recovery installed (i.e. ClockworkMod), and root access gained to your OS (controlled by SuperUser app).
You should let us know your specific software version, so that you can be directed to the right place. I believe that there are methods to root almost ANY software version WITHOUT wiping data (although the procedure may differ), but I'm not 100% about that.
EDIT: Oh, and to answer your question about "upkeep and maintenance", the only thing you really gotta realize is that you will NOT want to accept any "official" updates that VZW pushes out. That can have bad consequences, and is why many suggest NOT running stock OS after rooting (because custom ROMs won't be offered updates, but stock OS will). If you root, you do naturally accept the responsibility to maintain your device. If you're not cool with that, you may want to reconsider. (See #7 in my FAQ).