In Maya, the shelves on the top (displaying things like "Paint effects" and "hair") and the side (showing the transformation tools) disappeared, how can I put them back on?

EDIT: Never Mind,...

Thanks, I'm just used to working with google sketchup.

Okay, in this tutorial here (http://www.geocities.com/susantio/head01.htm) in one of the steps it tells me to delete half the sphere... how is that done?