For lots of information visit Brycetech http://www.brycetech.com/index.html . Read the tutorials from the left hand menu, specifically Animation and Camera Animation. These should tell you most things about positioning, keyframes, etc.

There was another tutorial I can't find now that explained path editing better. Here's part that I can find about the nodes.

Press an hold alt and click on an empty portion of the path to create a new control node.

Click on the node Press and hold alt and drag the mouse to twist the point.

Click on the node Press and hold C and drag the mouse to change continuity at the point.

Click on the node Press and hold T and drag the mouse to change tension at the point.

Click on the node Press and hold B and drag the mouse to change Bias at the point.

These are a very rough way to make the path bank, make the turns sharp, etc. There needs to be a node interface written that allows the user to type values in to fine tune the settings. As it is I suggest minimal changes, practice, and save a copy of your work before you play around.