Keep in mind that colors change when you shoot in black and white.
Reds will turn black, and shades of dark grey. This includes redness in your skin. Foundation isn't really a necessity for black and white, as the nature of the medium tends to smooth and perfect skin for you. Just make sure to cover any redness, and just spot conceal as needed.
Blues, reds, and purples tend to become much darker than they really are, warmer tones tend to come out much lighter.
Here's a helpful link for some really good information on working with black and white photography and makeup:
http://www.jurgita.com/articles-id146.html