Question: What are some grilling tools that a beginner should have when purchasing a new grill? Additionally, are there tools that are useful for the more advanced outdoor cook?

Answer: 
The basic things that you need are:

* Grill brush to clean the grate
* Large tongs to get food on and off of the grill

With that, oil to oil the grate, fuel, and quite possibly aluminum foil you will be grilling.

A grill basket of sorts can be very useful. Metal skewers for making kebabs are great if you like that sort of thing and don't want to spend a long amount of time soaking wood skewers so they don't burn to a crisp.
I have a wide, flat knife that can be used as a spatula; I find it really useful. Everything else has pretty much been mentioned, but I would suggest a pair of tongs with decent teeth on them. It's very disheartening when that burger or steak slips out of your grip and into the coals or onto the ground.