Computer Illiteracy Strikes Again

Please, could or would someone explain the difference between "(My) Reading List" and "Google Reader"? (I read the Help section, but I'm still confused.)

What is "feed"?

Also, does anyone else get an error message when you click "Publish Post"? I often do. Sometimes my post shows up as a draft, and other times it is completely gone (like just a few minutes ago - grrrrr).

Thank you. (Seems all I do is ask for help!)