The Database Programmer blog is a great resource for learning about how to design your tables:

http://database-programmer.blogspot.co.uk/

This crib sheet is also very useful for understanding the various concepts and diagrams used:

http://www.cthullen.s5.com/miscp/data_modeling.html

The "Data Architect" role is an ambiguous term that often means different things to different organizations.

Here's my list:

- Understand data normalization and modelling
- Knowledge of how the databases (relational or otherwise) your organization uses work
- Be able to create an understand entity relationship diagrams (ERDs)
- Be able to work with the business stakeholders to understand their data needs and convert them into data models
- Be able to create high-level models of the entities and data flows of a business. This is to enable "at-a-glance" understanding of how the business works.
- Help the business understand what data assets it has; their value, how they're maintained, etc.

In some organizations a data architect may work mostly/entirely on the higher-level designs and concepts. Others they could be working on the physical database design. It depends on the company and person!