If you need to get up to speed on marketing basics Knowthis.com is a great website to start with. It includes a number of tutorials which give background on topics such as market research, customers, product, distribution, price and marketing management.
I was interested to see how the site came about:
In November of 1997 a conversation between a university marketing professor and a university business librarian brought to light the lack of a centralized Internet resource dedicated to the field of marketing. This conversation was the starting point for building an online directory of marketing resources. By October 1998 the project moved under the domain name KnowThis.com where it remains today. Over this time the site has grown from a web directory to a comprehensive site that includes tutorials, articles, forums, links to industry news and much more.