I recently purchased domain names for my sites hosted here. I also transferred an existing domain name to my new registrar and moved the hosting for that website to here from it's former host.

So far, so good.

I've entered the correct nameservers on the registrar site and entered the custom domain names here. No problems. Everything is working.

At the site that I transferred, I had a custom email address. I planned to recreate that address. Email account and service is supposed to be provided by my registrar.

However, when trying to create the email at my registrar, the instructions state -

'If you are using an email account you purchased through us and your domain is hosted through another provider, you must update your MX records with your hosting provider.'

Question - is my domain hosted here, or is it just my website? Or are these the same thing? How do I update the MX/CNAME records?

It costs $5 and it is through google apps. Jump on the livechat for help and to sign up.

how to pay? can somebody give me a link?

go here http://livechat.zymic.com/ and they will help you.