Hi Julie,
The edit button for selecting lists, columns, etc is what I circled in red in the previous post.
To get to this interface, you'll need to choose ezEdit from the web part menu. Open the menu by clicking the little triangle (circled).
See Attached
If you can't see the triangle, go to Site Actions -> Edit Page and click Edit for the web part.
Just for reference, the appearance of this triangle is dependent on the Chrome Type whose default is set by the web part zone. You can usually override this in individual web parts by choosing the Chrome Type "Title Only" in the Appearance section.
Clear as mud? 🙂