Well the easy answer is to just read the rules on the 1st post of the Tag threads, but I will give you a quick summary. There are 2 games that I play in regularly.
How to get started: Look at the end of the thread and find out what the current tag is. This will be a pic of someones motorcycle in front of some sort of landmark. You then have to figure out where this pic was taken and then ride your bike to that place and replicate the pic as best you can with your bike. Sometimes figuring out where the tag is, is harder that riding to it.
The 1st person to upload a pic of their bike in front of this landmark wins. This is where smartphones really help. If you cannot load the pic remotely then you run the risk of getting "Bruced." This means that you took your pic before someone else but while you were riding back to your house to upload the pic from your home computer someone else took a pic and uploaded it before you did.
Ok so now that you won the tag you have to put up a new one. Again this will be a pic of your bike in front of something that is inside the borders of the game. Give a few clues and let everyone else try to find your tag.
Both games are very similar with just a few differences:
State Game is anywhere inside the state of South Carolina.
Upstate Game is inside of South Carolina but north of 20 and west of 77.
Posting a New Pic:
State game you have 24 hours to put up a new pic after grabbing a tag.
Upstate game you have 6 hours to put up a new pic after grabbing a tag.
One more tip: If you want to play start taking pics of your bike in front of interesting things. You can use old photos to place a tag so it is nice to have some ready to put up after you grab a tag. (you cannot use these old photos to grab a tag, if for instance someone else puts up a tag of something you have already taken a pic of your bike in front of.) You stll have to ride out there and take a new pic.
Anymore questions just let me know and welcome to the game.