Hi Courtney. If you are supposed to get in touch with someone who knew the author, you might try to contact Douglas Gresham, Walter Hooper, or Jill Freud. I would suggest you contact the C.S. Lewis Company at:
The C.S. Lewis Co. Ltd.
First Floor
Unit 4, Old Generator House
Bourne Valley Road
Poole
Dorset
BH12 1DZ
Tel: 01202 765652
Fax: 01202 765665
Have you looked at the information available under the other tabs on this website - faq, bio, papers, etc? There are some pictures under the multimedia tab.
As far as criticism of his work goes, there were many people who disagreed with his writings. For example, his close friend J.R.R. Tolkien did not like The Lion, the Witch, and the Wardrobe at all, and begged him not to send it to a publisher, thinking it would be ridiculed. And many of his Oxford colleagues did not approve of his non-fiction Christian books.
Good luck - it sounds like an ambitious project!
:)