It was originally intended as a children's book, but Michael Rosen's Sad Book is very well-written and has helped lots of adults (and children) to cope with grief. He wrote it while he was struggling with his own loss of his son. I'd also recommend the Griefcast podcast by Cariad Lloyd. She has a different guest each week and they discuss different aspects of grief. I have related to a lot of the feelings they have talked about; maybe you'll find some use in it, too.