Hi,
How do you save personal information stored in Kontact (eg. addresses, emails,
to-do's, etc.) into a location of your own choosing? I want whatever information that I've saved in Kontact to be automatically stored into a folder of my choosing.

Addressbook and calendar currently work with a plugin system called KDE resources.

You can change the plugin settings from with Kontact and from Systemsettings -> Advanced Tab

Default setup has one local file resource for each data type (e.g. contacts) using a file location under .kde/share/apps
You can change the plugin settings to a different location and/or add another file plugin for that location.

Mail directory is a bit trickier since there is not GUI option for that, though I think there is a HOWTO or FAQ somewhere on userbase.kde.org for it.

Cheers,
_