Have you seen the Tamiya BTCC 850 Wagon? Well, for the last 5 days I've been putting decals on it - and still not quie done yet (although the toughest part is hopefully over. It was a nightmare! But I had allies - Q-tips, two brushes, Humbrol DecalFix and the best one - Braun Silencio 1200 hairdryer!
Take your time. As you can see, I did not rush it and it came out quite OK (it was the first time I undertook such a huge (HUGE) decalling project). Do one at a time and give it time to settle. And you really should wash the model before putting on decals. And never EVER touch the sticky side of the decal with your hands. Don't touch it the decal at all. I slide the bigger ones from the backing paper in place and pick the smaller ones with a brush.
And the paper that came with the decal is there to protect the extremely fragile decal surface.
may I give one more advice? Cut the exess film. Cut it as close to the coloured part as you can (dare). trust me
Good luck
P.S. you can wax over the decals, but be very careful.
Alex