Heya Bruce,
I'm not too sure what type of charts you are looking for. To my knowledge there are no Navigational Sectional Aeronautical Charts or Airport Charts included with FS 2004. Here's a list of websites for charts that I know of (someone else will probably think of more).
http://www.fscharts.com Rather simple charts for use with Flight Simulator. Not FAA approved.
http://www.airnav.comI'm a big fan of this website. I use it for all of my Pre-Flight Planning needs. It has all of the information about the airport. Comm, Nav, ATIS, Tower and Ground frequencies, runway weight limitations, SIDs, STARS, and everything!! Beginning in July 2004 it even includes a FAA approved Airport diagram chart showing the runways and taxiways (in PDF format--you have to have the Adobe reader to view or print these charts) !! You can even print out the airport diagram as well as SIDs and STARS for future reference. This website, unfortunately, only covers US airports and some US affiliated areas.
I created myself a new folder in the Main FS 2004 directory called Airport Information. I have other sub-folders within named by states (i.e. Alaska, Alabama, California, etc.). I have created Internet Explorer links for these airports in these folders for future use. That way I can just go click on one of these links and get the latest updated airport information.
If you're looking for Navigational Sectional Aeronautical Charts I really couldn't help you without knowing what charts in which country you're looking for.