the easiest way to find out if your rooted is to go into the app drawer and see if there is an app called "Superuser" the icon will look like this
if that is there...then you are rooted...
As for the SBF...basically what you need to know here is that the SBF is going to be a complete system file...you're going to use a Windows based program called RSDLite to flash your phone with the most recent version of Froyo...
the process you're going to use is the exact process that Motorola or Verizon would use to flash your phone...
once you are done with the SBF you will have 3 options for getting on Gingerbread...
1. Take the OTA update...not rooted...may never be rooted
2. Manually install the OTA...not rooted...may never be rooted
3. Manually install the pre-rooted OTA
the post right above mine is a perfect link to start at...that will walk you step by step through the SBFing process...once that is complete...we will get you on GingerBlur...
OH!...i hate to say this but you're probably going to lose your data on this journey...you MIGHT be able to SBF without a data wipe...but i think its going to send you into a bootloop...