All good advice, simply follow it. Whois will always tell you what is. Any search for "domain registration" will return so many places to register a domain you won't know what to do with them all.
Bottom line; When you get your domain keep your registry key, your login, and who you registered with. Make sure you make notes on when it will expire. Do not rely on someone else to contact you and remind you! It's your domain, manage it and make sure it doesn't slip away.
Best wishes,
Dan Townsend
www.iphonedomain.com