A great starting point on executive function is Peg Dawson's book Smart But Scattered. Lots of help understanding where and what the problem points may be, and practical ideas for dealing with them. She is especially good at helping you think through how to dig down to the underlying causal issue that needs help, as opposed to the more visible symptoms.

Another good resource is the website ADD-itude. Rather overwhelming sometimes (where is the irony emoji?), but it has a ton of practical suggestions for supporting and building executive function challenges.

http://www.amazon.com/Smart-but-Sca...1144&sr=1-1&keywords=smart+but+scattered

http://www.additudemag.com/resource-center/adhd-at-school-better-organization.html