Ryan,
Your root CA certificate needs to be in the TRCA store. You can find this by opening the Certification Authority MMC on your CA server, going to the properties of the CA, clicking "View Certificate", and selecting the "Copy to File" option on the details tab. You can also install it via the /certsrv website if you installed the CA with that option.
Once this is done you'll need to import the certificate that was generated from your request into the local machine store of the OCS server. To do this open the certificates snap-in in MMC against the local computer and find the import option in the right click menu.
Z