> However, I've forgotten how to turn on wifi networking from rescue mode.
> Can anybody point me to a tutorial?

You could use the "iw" commands:

man iw

which should give you the info you need.
       iw - show / manipulate wireless devices and their configuration"

if you would like to review a tutorial:

has a decent write up if a bit dated.  Should get you pointed in the right direction but everything still looks good on quick review.