I'm not sure where there is a resource that puts this all together for you, but you do need to make sure that you own the domain when you register it through your web hosting company.
All you generally need to do is ask - assuming that the web hosting company is providing the domain registration for you - and not simply passing along the costs to you from another Registrar or Reseller. If he is, then you can just register your domain yourself at your Registrar of choice. Just ask your hosting company what to put in your domain record for nameservers, and you are all set.
However you register your domain, you need to make sure that your email address is the admin contact for the domain, and that you can manage the domain information directly through some form of web interface at the domain Registry.
Most web host will sell you a domain as a reseller. This means they are not the Registrar - they use someone like OpenSRS or eNom as their Registrar. This is fine. You simply need to make sure that you own the domain, and you have control over managing the domain.
Why? Because you may want to move your website someday, and if you don't own your domain, if the webhost does, you cannot take the domain name with you when you move.