Basics  

Tools required
This is a listing of the types of tools that you will need as you build your kit. 
Minimum
Socket set - Standard and Metric 
Screwdrivers - phillips and flathead 
Wrenches - Box end and Cresent 
Flaring tool 
Floor Jack 
Jack stands 
Hammer 
Electric drill 
Electric grinder 
Electric metal saw 
Assorted Drill Bits 
C clamps and Spring clamps 
Optional
Air Compressor 
Welder 
Drill Press 
Skills required 
Welding 
It will be necessary to use a welder in constructing this kit. This will be required for the stretching of the frame as well as when parts have to be fabricated for the car. If you are not familiar with welding, you may wish to hire a professional to do the structural part of the kit or possibly take a course through your community college. 
Electrical Work 
You will need to be able to make electrical connections and splice wires into the existing Fiero wiring harness.  Because the body is made of fiberglass and does not conduct electrictity, it will be necessary to run ground wires to all connections that are made in the fiberglass. 
Body Work 
When fastening metal components like the hinges to the deck lids, the methods that are used are as follows: Grind the surface to which the component will be fastened to remove the waxy coating. Test fit component to make sure there is a good fit. 
Mix and apply a coating of bondo to the component similar to applying butter to a piece of bread. Apply the component to the surface and if necessary, clamp lightly in place. Let bondo dry thoroughly according to manufactures instructions. 
Cut a piece of fiberglass matting or cloth to allow an overlap of at least 2 around the component. Mix up enough resin and hardener to saturate the matting or cloth. Take necessary precautions to cover the threads of any bolts to make sure they are not filled with resin. 
Additional Reference Material
I would also recommend that you get a manual dealing with the care and maintenance of the Fiero. One such book is a Haynes manual as shown below. There are other manuals as well that you may want to pick up. The reason to have these books is to answer any questions that may come up in dealing with the actual mechanical aspects of the car. For example if you are planning on removing the engine. These manuals will be invaluable assisting in these tasks. 
These books are available at most autoparts stores.