Did you try using the Game Explorer here? Or typing "Reti Gambit" into a search engine? I did and got several hits right off the top. You may have to check them out yourself to decide which are the "best places" to research this opening, whatever it may be.
http://www.chesscafe.com/ This is a good all-around chess site for research and study
There's a series of youtube videos about it from Thomas Johansson, author of the book The Fascinating Reti Gambit. Here's a link to the first video:
http://www.youtube.com/watch?v=w53jqnNrOo0
I've seen some posts from Johansson about the King's Gambit over at the chesspub.com website, so you might try there, too. I don't recall seeing posts about the Reti Gambit there, but I don't read that site very often. (I think he uses the same name to post there as he used for the youtube videos-- taljechin)
Best places to get good resources to help me get more familar with the reti gambit