My Vanagon just faithfully took me on a 300 mile trip and now will not crank!

This same thing happened the day we were to leave town week ago.  But after
several tries, it crank and I went on this trip, over several days, with another hard
cranking instance.....

Now it won't crank?  Good battery, good turn-over, etc. sounds like no fire?  The fuel
pump is making noise as if it's OK......

If no fire, where do I start?  Unplug spark plug wire and ground to check for spark?  Then 
what......?

Any advice is greatly appreciated......

Larry 
Georgia

word_aag@comcast.net