This look pretty sweet for your first Independent model.
I agree with the comments about your topology thus far.
Try not to add more Geo until you really need it. Slowly build up the detail.
Using the Poly by poly method works pretty good. It's nice because you can nail down the edges flow right away. I prefer (as of recently) to use the Box modeling method. I like to be able to nail the proportions of a character, then move onto the edge loops. But it's all the same. Once you've learned the tools (make friends with the Split Poly tool) you can make a head out of anything.
"Your weapons are no match for ours! People of Mars, surrender!"
"Um, this isn't Mars. This is Earth."
"Earth? Earth-with-nuclear-weapons Earth?"
[long pause] "Friend!!"