If you're looking for a good book on the occupation, I wrote my thesis on the occupation, and used these as sources.

The German Occupation of the Channel Islands by Charles Cruickshank. This is the official history of the occupation, and goes very in depth. It uses primary sources from the British, German, and Islanders to create a complete picture of the occupation.

The Model Occupation by Madeline Bunting. This provides a more critical view of the Islanders, and their relative lack of resistance to the Nazi occupation. It looks into where the line between non-resistance and collaboration is drawn.

Channel Islands at War: A German Perspective by George Forty. Looks at the occupation from the German side (duh) from the generals in charge to the common soldiers. It's pretty interesting, but without a decent background in the occupation already, it's not really holding up a mirror to anything.

I used plenty more books and other sources, but these are the ones that sprang to mind.

Finally, if you want some historical fiction on the subject, The Guernsey Literary and Potato Peel Pie Society by Mary Ann Shaffer. It came out about a year after I wrote my thesis, and provides a nice touching off point for getting anyone to listen to me talk about the Channel Islands. Plus it's pretty good.

There was a quite good documentary (Kanalinseln im Krieg) on german television a few weeks ago (I just found, it's at least a year old), and I don't know if those ever get translated into english.

But it might be a starting point, and maybe you can find a subbed version on the net

the BBC has also some stuff

Well I'm no expert, however I've done some digging & found these gems:

Island at War - A dramatised documentary series on the Nazi occupation. Here's episode 1

Hitler's Island Madness - History Channel documentary on the Nazi occupation.

Life In Jersey under German Occupation: An Interview with Bill Morvan - A Veteran recalls what his life was like when Jersey was under the Germans. Part 1 & Part 2.

The Channel Islands at War - John Nettles tells the story of Nazi occupation.

BBC: History also has a fairly extensive page on the occupation.