thanks for you advice Mastone, but i kinda feel using curves on a head model is a pretty out dated way of doing things. I saw a head modeling tutorial that built up a head with curves or whatever and it looked rubbish! I prefer the single poly method.
As far as the edge flow goes, I checked it and it all works fine.
(you can check your edge flow by selecting the edge and then pushing the up arrow on the keyboard. you can then cycle through the edge loops or if you want a better view of it you can hold ctrl and drag the mouse down to convert to faces.)
As for Zbrush my first head model was nothing more than an egg on a stick
fair enough it looks kinda weird, but thats just cos i never finished it. So you can import your model at any stage into ZBrush.... Well thats what i've been led to believe.