using photoshop? crop the photo in half, and drag it onto your UV, set the opacity of your new layer to like 30% or so.... depending on what mesh youre using the eyes may be more slated in either direction. Ive found the best way to line them up, is to concentrate on the more important areas of the face first (nose, nostril, and underneath the eyes) I usually make selections around these areas and using transform, move & rotate them to the correct positions. Then use the clone tool, to fill in the gaps afterwards. Also try using Snow Sultans seam guides, theyre great for lining stuff up.

Hope this helps.....

"If toast
always lands butter-side down, and cats always land on their feet, what
happens if you strap toast on the back of a cat and drop it?"

Steven Wright