For most DBAs, normalization is an understood concept, a bread and butter bit of knowledge. However, it is not at all unusual to review a database design by a development group for an OLTP (OnLine Transaction Processing) environment and find that the schema chosen is anything but properly normalized. This article by Brian Kelley will give you the core knowledge to data model.
The strength and holy grail of relational databases lies in the very name: relations. Microsoft has put a good deal of intelligence and cunning into query optimizations, caching, indexing and execution plans to make the process of finding related records even smoother and faster. This small article, however, will try to shatter the very sacred notion of relational databases.