I might suggest as possible models khanacademy.org and lumosity.com. Lumosity is a collection of games which claim to provide brain training which can improve mental capacities. Khanacademy is a site for people to learn mathematics and other subjects. The useful features each contains are in lumosity's case games arranged around topic areas that can help people develop skills, and in khanacademy's case short, ten-minute videos with small easily digested pieces of information and a skill tree with links to materials where you can master skills topic by topic before moving on to more complicated skills.