http://www.amazon.com/Complete-Book-.../dp/0936240148
My son got this for Christmas last year and it's been really helpful to him.
He's learned a few knots and the difference between Texas rigging and Carolina rigging from the book, whereas I was having trouble teaching him. He's 11 now.
I've also found it really useful for learning some new knots and the fine differences between some of the tackle that I don't use frequently.
The book gets good reviews on Amazon, and if you're looking for some small gift ideas for Christmas, this might just be the right thing.
