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: 
In addition to what others have said, you should have TWO of each meat-handling tool (tongs, mainly). That way you can use one to handle raw meat, and one to remove cooked meat.
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.