Modeling (UML etc)

Cardinality Notations - Entity Relationship Diagrams (ERD) - The Software Design Center

http://www.smartdraw.com/tutorials/software/erd/erdcardinality.htm

Increase productivity, communication, and collaboration using UML visual modeling platform.

http://www.visual-paradigm.com/

Practical UML??: A Hands-On Introduction for Developers

http://dn.codegear.com/article/31863

UML tools for software development and Modelling - Enterprise...

http://www.sparxsystems.com/