There are not very many books available that try to cover cellular signaling at an introductory level, but this one does a very good job of it. It is well written and at a level appropriate for people with a range of backgrounds. I think that as long as you've had a couple of semesters of biochemistry or cell or molecular biology, you should be able to understand the material. I really liked the way the book was organized, and I appreciated the inclusion of quantitative approaches to signaling. Although I don't use RasMol, the emphasis on protein structure was appreciated and the book makes it easy to use other free programs to examine the structures of the proteins that are discussed.