At the registrar, I enter the nameservers ns1.domain.com and ns2.domain.com. Should I also enter the IP addresses? Will it help or hurt?

I believe you have to unless it doesn't ask. =)

Some of the sign-up scripts actually go out and find the IP automatically saving you the hassle of doing it yourself.

You might want to check with the provider though.

I'm using Stargate. Under the Name Servers tab, they provide input fields for both name server and IP address. Currently, I only have the name server fields filled out (ns1/ns2) and the domain name seems to be resolving okay. Guess if it won't hurt, I'll go ahead and enter the IP addresses as well.

Because name servers all have to be registered as hostnames with the InterNIC, you do not necessarily need to include the IP addresses, the name servers should resolve at the root name server level.

That being said, it can never hurt to give too much information in cases like this :).

Thanks all!