http://www.linuxgraphic.org/section3d/blender/pages/didacticiels/head-subsurf/didac5-ang.html
I am having trouble on taht exact step. I cant figure out how to delete half of the face. I am a MAJOR newbie i actually just started on…Thursday night. So ive figured alot of stuff out and started to make a 4th of july fireworks show which should turn out good. But back to the subject can anyone help me with this step? Any help would be MAJOR appreciated.
Welcome to the wonderful world of Blender! 
Box-select the half you want deleted (B-key), and press the X-key. A Delete menu will pop up, from where you click “Vertices”.
Thank you very much! I needed alot of help.
Woah!!! This tutorial is so old! I wrote it when i started learning subsurfs… There are newest of better way of modeling heads, now: edge loops are among them. But I suppose it’s a tutorial still worthy for newbies and general purpose organic modelling.
I’m glad someone still use as reference 
though. Hum… Wondering if I should write another one, using more recent technics… Anyway, don’t have time for now; lol!
Unfortunatly that didnt work for me for some reason. I did all that stuff but it didnt work still. hmmmm
do not put yourself in anger OvilS I propose another tut : https://blenderartists.org/forum/viewtopic.php?t=21066&postdays=0&postorder=asc&start=0