most of these are good, but i don't see any describing clothing wrinkles, which is a big sore spot for me, or shadowing. And most of the hand references are good, but there are many that aren't there that I would like to see
also, lots of these are for digital manga drawings on the computer for those fancy programs on the computer. i wish there were more traditional hard copy tutorials for people who draw with pencils and pens. ( like I do because I don't have any paint program besides Microsoft office paint.)
but like I said some help and some don't. But most are good.
if the program is an issue and you want to do digital art, you can always download gimp it's free and it's basically photoshop for people who can't afford ps as for shading, just think of the photo as cylinders and blocks and shade them like you would those
sorry for the random comment //fades away into background