What is the best way to add a lead to program membership? I want leads to be identified as having membership with a program they haven't necessarily been through.
Do you mean adding leads individually? If so, you can look up the lead in "Lead Database", select the Lead and then at the top where it says "Lead Actions", go to "Programs" and then select "Change Program Status" and assign the lead a member status and they'll be added to the program.
You can use a smart campaign to do it in bulk. Identify the leads in the smart list, then use a "Change Program Status" flow step where you name the program and change their status to "Member"