Gene is NCBI's database for gene sequence and expression information. This database also links to information such as mRNA isoforms for a particular gene, pathways in which the gene participates, etc. This is somewhat of an one-stop location for obtaining important gene information.
Online Mendelian Inheritance in Men (OMIM) is a database that documents gene-disease relationships. This a database that will be useful for your studies in PCB3063.
1000 Genomes browser documents genetic variants in individuals of various ethnic backgrounds.
Genetics home reference is a database catered to consumers and contains information regarding genetic influences on disease.