Moving The Map: Either use the icons in the top left of the map to zoom and pan - OR - pan by grabbing the map anywhere (left-click and hold) and drag it around. You can zoom by double clicking on an area (not an icon).
Seeing Places: Click on an icon. Remember that when the map is zoomed-out, many icons may be hiding one behind another to zoom-in to see them all. Sometimes you need to click an icon twice to see the content (it's a database thing).
Adding places is simple and is done in four steps.
Note: if you already have an account (perhaps you have added content before), use the right side of the screen to sign-in with your email and password.
You can comment on a location - perhaps you visited or know details. Just click the "comment" button and it's the same as entering a location.