I just purchased an original 2g iphone 8g on ebay. The phone has been restored back to factory settings. I'm not sure it will come with a sim card, but I plan on taking the sim card out of my BB and going from there. Is this the first thing I do? Can you even go onto itunes without a sim card? I probably sound ignorant. I am on this, but I'm teachable and somewhat techy savy... please help
Are you on AT&T? If not then you'll need to hactivate. This means you have to jailbreak it to access the springboard in order to do anything at all. You then can choose to upgrade to 3.1.2 (if it is not already but if not you should cuz it's a nice little upgrade) then search for a guide on how to unlock a 2G iphone. There are plenty of guides out there.
If you don't know how to hactivate, you can also find guides on how to jailbreak a 2G on 3.1.2. The initial jailbreak to access the springboard (if it isn't already) you'll have to find out what firmware it is on to know which tool to use.