I dont understand why he has separate web and email hosting, does Ready hosting offers some kind of ActiveSync services or higher spam protection?
If not you can cut cost down and just go with GoDaddy for web and email.
Back on topic, yes you need to poing nameservers to godaddys, and on godaddys panel change mx to ready host.
No need to change name servers. Just log into his Network Solution control panel and add an A record to point the domain name to the GoDaddy's IP address.
That should do the trick.
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