Any good, useful drawing websites?

I am a sketch artist. I love to draw and not to be self-centered, i think i am a great sketch artist. I can draw well, i’ve got pretty much all the details down except one problem, I cannot draw people.

Im great at landscaping and flowers and scenic areas, but i just cannot draw people, and it really bothers me.

So if anybody knows and websites, books, or tips on how to draw distictive facial features, please help!