Save for Summer Highlights

What is "Save for Summer"?  
How do I enroll in Save for Summer? How can I update or cancel my enrollment?  
If I cancel my enrollment in Save for Summer, when will I get paid out?  
I was enrolled in Save for Summer last fiscal year. Will I be automatically enrolled the next fiscal year?  
How are Save for Summer payments made during the summer?  
Is there an alternative to Save for Summer if I still want to set aside money to pay myself during non-working months?