So looking at putting a cool logo (simple outline, just black) on all the shields of my Daqan army. Whats the best way to do that? Is there a way to print decals?

Sure is

http://www.staples.com/decal+paper/directory_decal+paper

Laser or Inkjet, based on your printer.

White decal paper, printed through an inkjet printer. Once the ink is dry you need a spray decal bonder, spray your decal page with it. Paint gloss coat on the area you want the decal to go. Then cut soak in water, while soaking I recommend using microset on the surface before sliding the decal into place. Apply decal, remove excess microset with a q tip. Then once dry apply microsol. This is a solvent that will soften your decal and conform it to the surface. Apply, while excess with q tip. It's going to look bad until it fully dries, don't touch it! Trust the solvent. After it's dry check to see if the decal is conforming to your liking, if not apply additional coats of micrsol. Let dry each time. Once the decal conforms to your liking, once it's dry mat varnish and ta da!