Need some guidance, from a Keanu Reeves type programmer.

Maybe this isn't really that advanced, but I'm not a programmer per say, more so a designer. I've been asked to put together shopping cart (more like shopping mall) type system. Basically, you can buy the product online - which was the easiest part of the whole thing. BUT, the next thing they want is for the ability to have distributors work from online.
How I was told this would work is that people would sign up online to be a distributor, then be able to give potential customers links to be able to buy the products, but the links would be specific to the sales person selling it to them- at which time you receive a percentage of the product sold to them. However, the plot thickens. You can also go one level further and sign up another member, in which case anything the next member sells online will also see you receiving a percentage of that moola. And from there the pyramid scheme ends, but you can continue to sell more product if you wish to continue with signing up multiple people and collecting a percentage of their sales.

So what I'm basically asking is where to really start. Obviously this isn't something I see as simple, but maybe to someone else this is easy-peasy. Any kind words, or advice to set me in the right direction?

If you are not opposed to forcing your shoppers to register and log in, then you can use a simple database to keep track of the relationships between shopper and, uh, "marketer". At the time of registration, the shopper has to enter the name of his/her marketer. Anything a shopper purchases will then be stored in this database, so when it comes time to cut checks for the marketers, you can use a simple database query to select all sales made by his down line.

If you do not want to force shoppers to log in, this same general design can still be used, but you'll just have to force your shoppers to enter the name of his/her marketer at checkout time.