As well as looking at the Print production manual, (see notes here), I have found the print handbook very useful. Here are some of the things I have learnt:
Spot Colours
It might not be possible to print the same vibrant colour in cmyk as it would be to print it as a spot colour. For example, for a metallic or fluorescent colour, you can't get anything near this using cmyk, so you would need to add a spot colour, to give your piece the extra impact. It is not necessarily more expensive, an using just one spot colour instead of the four plates using in cmyk printing can actually make a job cheaper.
Example of Printing Plate
Paper Sizes
Recommended links to look at:
