The following descriptions were taken from Bob’s site UncleBob.com.
Single Responsibility – A class should have one, and only one, reason to change.
Open Closed Principle – You should be able to extend a classes behavior, without modifying it.
Liskov Substitution Principle – Derived classes must be substitutable for their base class.
Interface Segregation Principle – Make fine grain interfaces that are client specific.
Dependency Inversion Principle – Depend on abstractions, not concretions.
As I write more information on each of the concepts above, I will link to the post from this page using the section above. You should be able to use this as an index page to see when new updates are added. Please check back periodically to see if there are new entries and provide feedback.