Go into your E-junkie Seller Admin > Edit Affiliate Program Settings screen -- your sign-up link code is on that screen in the yellow box. Just copy that code and paste it into your Web site pages, wherever you want to recruit Affiliates to join your program.
You may find this forum thread helpful to get a fuller picture of how our Affiliate programs and the various link types work:
http://www.e-junkie.com/bb/topic/2690