Track traffic source through redirected domain???

I bought a domain name through namecheap and plan to redirect it to my affiliate link. I am just wondering if anyone knows a way to monitor the traffic and the referring url that clicks my (redirected) link?

I plan to promote my link through several different sources and would really like to get an idea of what is working and what is a waste of time. I also plan to buy a few more domains (all redirected to the same link) to test if the name actually makes a difference in my campaign.

A while back I used a url shortener (bitly I think) that at least gave some traffic stats but I don't think they went into detail like the referring url and such. Perhaps redirecting to a shortened link would be an option if I can't come up with something better.

I also have a hostgator account if I can use that to serve the purpose... I just dont know much about it and am actually just learning to set up a real site.

Any suggestions are appreciated...