Last season we moved substitute lists from the registration process to user pages. After registering, you can go to your user page ("My account" in the upper right), pick the “Sub Lists” tab, and add (or remove) yourself from sub lists for all leagues that support sub lists.
On the listing for each league that you are registered for, you can see both the current member and sub lists with phones and emails. Keep in mind that some members have chosen to not share emails or phones - so you may have to work a bit harder to get in contact.