Adding Color to Black and White photo in photoshop

So I was searching around and found some cool sites that gave tutorials on how to add color back into a black and white photo. Check out the following:

http://www.astahost.com/info.php/Photoshop-Tutorial-Adding-Color-Black-White-Photo_t7741.html

http://emptyeasel.com/2008/04/29/how-to-add-color-to-black-and-white-photos-in-photoshop/

http://www.absolutecross.com/tutorials/photoshop/photos/colorizing/

http://blog.lorrifreedman.com/index.php/2008/09/24/bringing-color-back/