Announcement Lists Help

I am trying to figure out exactly how announcement lists work. I see a bunch of text boxes such as “Subscribe URL”. What exactly do these do and how do they work? I didn’t see anything on the Wiki and haven’t found more help on it. If there is a link to more help, please let me know.

I would like to create a link on my site that allows people to subscribe to the email list. I figured this should be an easy thing to do but I’m not seeing it. Right now I see it is easy for me to add addresses by hand. Now I want to allow people to opt into it from my site.

I feel stupid since I am quite savvy with technology.,_PHP,and_Databases/_Announcement_Mailing_List
Here are a couple I found on the wiki. Any more questions just yell.

My website