Needing A Database Design Book
Both of these guys authored several books, but I'm going to link to their blogs in case you want something more immediate.
Louis Davidson: http://drsql.org
Paul Nielsen: http://www.sqlserverbible.com/
SQL Antipatterns is worth a read for some hints on what you shouldn't do and why not (and under what circumstances those rules can be legitimately ignored).
Database in Depth: Relational Theory for Practitioners, by C.J. Date provides a great, short and highly informative introduction to database design.