peeper,

There is such a wide variety of models these days, from micro size to mega monsters, that it may be hard to make any useful list of spare parts. Even if we limit it to 40 size glow powered trainers it depends on the type of plane, rubber band mounted wing vs. bolt on wings etc. If you want spare parts for yourself then wait until you decide what planes you will be flying and then get spare parts for it. If you are looking for a list of spare parts to bring to a field to share with others then here is a start:

Metric and SAE hardware, bolts nuts washers etc.
Include some long 4-40 socket head screws for mufflers and some 1/4-20 nylon bolts for wing mounting
also some tiny wood screws for hatch mounting
Prop nuts
Wheel collars
rubber bands (esp #64)
CA glue
5 minute epoxy
glow plugs
fuel tubing
band aids
Spare glow starter and battery
Packaging tape for quick covering repairs