try looking in the top left corner - there should be a small box that says something like animation, modeling, dynamics, etc... Just click on the box and select modeling and and you should see the edit polygon menu come up. Not sure if that's how you do it on the latest version of maya though..
Well, if you look at the shelf, many of the common poly editing tools are there (face extrude, edge, extrude, split, cut, merge, etc.). If you look at the menu at the top, "Edit Mesh" would contain all the poly editing tools. It used to be called "edit polygons" in Maya 7 or earlier. You really need to hit "F1" and start reading through the help files so you can familiarize yourself with getting around the UI.