Not very proficient in DNS so grateful for any input you can give ..

I have to turn off recursive queries on our DNS but when I do names cannot be resolved. Our Primary and Secondary DNS servers use internal addresses and our clients are set to query those servers for their DNS. There is an external address in our firewall that is NATed to those servers.

Looking through some of the posts in this forum I see mention of split DNS and suspect that might be my solution but am not at all familiar with this and wondered if there was a good beginners guide to it out there?

Is that the solution or can I do something else?

Thanks in advance!