Make sure that you have installed the linux kernel headers for your currently running kernel. By default, DAHDI will look for these in /lib/modules/`uname-r`/build. How to install stock headers varies from one linux distro to another.
Your drivers should now be up and running and ready for use. This should leave you with a basic /etc/dahdi/system.conf customized for your existing hardware. You will likely want to edit the file to suit your specific needs.