First off, I would definitely listen to your doctor when they strongly discourage something. In our case for example, folic acid was also a no-no.

Here's a book that was very useful to us: "The Cancer-fighting kitchen" by Rebecca Katz and Mat Edelson.

One more piece of advice on nutrition (I'm just the messenger here). Listen to your body, at different parts of the treatment it will tell you different things, your tastes will change etc. Also, you can't go wrong drinking lots of water!