Hi Owen
There are a lot more experiened technicians on this forum than me, however i shall try and give you my two pennys worth.
When it comes to Identification, as long as you can determine, wool & synthetic your going to be ok, dont worry too much about nylons,polypropelene, polyester etc, their synthetic, so clean as such
Axminster and wilton, your right to be cautious, and further studies of these textiles and their cleaning procedures should be sought.
When it comes to upholstery, carry out your bleed / burn tests and if in doubt walk away, i have on a few occasions!
i think by taking the course, your off in the right direction, the information given can seem overloading, (especially for a newbie)
As for further readiing, somebody else may have further book reccomendations, but your best way to learn is go out and start cleaning now you have this course under your belt, this is better than any course or book (in my opionion)
Finally dont doubt your own abilities, the knowledge you have gained in taking the course has already set you apart from most other cleaners in your town. You are heading up the right path
regards
john