re NMM - you need more contrast between the lightest parts of the armour and the darkest. Personnally the darkest I go with the shading is Scorched Earth. My colours light to dark are :-
Scorched Earth, Bestial Brown, Snakebite Leather, Bubonic Brown, Sunburst Yellow and then bleached bone for the top highlight and edging.
I use skull white to pick out points on the model that I want to really emphasise. I find that if you highlight everything with white it loses the shiny feel and just doesn\'t look right.
If you want examples of where to place highlights for NMM you can check out pics like Necroghast posted or look at examples of what the top 50 artists have done. Or look in the Articles section, there are a number of them on how to do NMM.
On the subject of posting WIP pics you can get a CMoN blog account ( free) which allows you to upload pics which you can then link to in the forums to show your pic in the posting.