Quick couple on "Zerocost speaker cables"

Planning on building a pair of Zanesh's DIY speaker cables - https://www.audio-forums.com/as-rediect/showthread.php?t=434&highlight=cost+speaker
I'll start with the really stupid question. I'm not that familiar with enamelled copper wire. I can get it from maplins though. Is the 'enamel' an insulating coating? When soldering, does this need removing first. If using bare wire for terminals, what's the best way tp strip it?
Also, is there an optimum thickness of cord?

 

yes .....to both

I try to remove it with a stanley knife blade ...but a hot flame will do the same ...though for me always leaves a residue.

As to thickness ....you can go as thick as you want but any more strands and it becomes very difficult to work the cable.