I have recently started grooming my yorkies myself...not because I want to, but because my hubby refuses to let me pay $40+ to send my babies to the groomers

Some men just don't understand, do they? But that is beside the point....
Since I am now grooming them myself, I really need to learn how to trim their nails myself. Up to this point, I've just been too chicken to do it. Because their nails are black, I just have NO idea where to trim them. And I know it hurts them SOOOO badly when their nails are cut too short, and I know they bleed and all that stuff too if cut too short. The LAST thing I want to do is hurt my little babies, so I really need some tips on how to trim their nails myself.
Any suggestions??

Any help at all would be greatly appreciated!