A great place to get portrait photos is Julia Kay’s Portrait Party on Flicker. Basically artists draw other artists. So you have to put your own picture up and other artists will draw you and you have access to all the other artist’s photos to draw and paint from. What is great is that you have permission to use the photos and they tend to be better than most selfies and snap shots because the artist know how to light themselves. There is also a bunch of public domain photo resources,just Google public domain photos.