Here are some interesting videos that might interest you regarding Annie Leibowitz, Henri Cartier
Bresson, Diane Arbus, Richard Avedon, Helmut Newton etc. I think you can get something different from these artist's work when you hear them speak about it. some more contemporary artists: Loretta lux, Samantha Everton, Nina Katchadourian, Daniela Edburg, Irina Davis, Rineke Dijkstra, Hendrik Kerstens, Dan Burn-forti, etc etc.
Check out this site for some excellent portraiture from England by many different artists who are using different styles: (here's one for you Joanna!) but his other stuff is great! (also!)
Also, when I mentioned the 'Creative Live" site, here is a small video from Bambi Cantrell that is on Youtube: She is pretty awesome and so is the second link to Sue Bryce. Both talk about working with humans!! and shooting and doing what they do.
and also about posing:
This not for everyone! But it might interest some of you.
Also, here is a really good tip for making some large reflectors which stand up on their own. Check out the video and skip the first bit and then skip forward to the minute: 2.51 to then end to make a reflector life size and you can also buy one of these insulation boards (polystyrene...I spoke about this) and half it (between 2 of you) and then you can take them on location with you!