Lewis,

The procedure for testing your crank shaft sensor, and just about every other sensor, can be found in any descent repair manual. Haynes and Chiltons both do a good and walk you through the procedure step by step.

Your lack of spark can be a number of things:
Bad battery
Bad starter
Bad alternator
Worn spark plug wires
Worn spark plugs
Inproperly gapped plugs
Blown ignition fuse
Oil or excess moisture in the spark plug wells
Low or no compression on the cylinder(s) (cracked head)
Bad ECU (car's computer)

There are many areas to check out here. Also, many of these things can be ruled out if the engine, though doesn't start, at least turns over. The 2G ('95-'99) turbo Eclipses are very popular cars to modify. If any modifications had been made to that car by you or a previous owner, they may have led to the problems you're having now. I get a lot of questions asking the very same question you asked. Unfortunately, there are so many things that can lead to no spark, everyone may have a different cause. If you get a Haynes or Chiltons repair manual, they can help better diagnose your problem. You can get them at just about any auto parts store. They cost around $15.

Good luck!