Basic scripting question

So I have a game controller object that controls everything. And within that script I have something like this:

var Player: GameObject;
var node : GameObject;

function Start()
{
   Instantiate(Player, transform.Vector3(0, 0, 0), Quaternion.identity);
   Instantiate(node, transform.Vector3(0, 0, 0), Quaternion.identity);
   Player.setStartNode(node);
}

and then in the Player script (which is attached to a prefab named Soldier) I have the following code.

var node : GameObject;

function setStartNode(startNode : GameObject)
{
    this.node = startNode;
}

But the problem I get is: 'setStartNode' is not a member of 'UnityEngine.GameObject'.

I kind of understand what is happening, but I can't really figure out how to fix this. I'm a little new to Unity scripting.

I think the issue is that the function setStartNode is not within the same script as you are calling it. Check the reference for Get Component http://unity3d.com/support/documentation/ScriptReference/Component.GetComponent.html to see how to access a script on another object. Hope that sets you on your way :)