Andree, you can eliminate the Ignition Switch as a possibility by checking
to see if your front heater blower works. If it, along with your headlights,
do not work, it's the ignition switch. Also, I think that the windshield
wipers are part of this circuit, so check them too. In any case, the
ignition switch comes to mind because it is such a 'classic' failure. Always
carry a spare. I think Bus Depot and the usual suspects have these for
around 14 bucks.
If you find that it is this switch, you can find installation instructions
using a simple google search. Also, I think BTDT at www.vanagonauts.com has
a good write up.
BTW when you post a question, you must include information on just which
model, year, etc. your van is, or expect a well deserved barrage of
scoldings from the usual Vanagon List Nazis!
Goold Luck,
Miguel