So how does one go about becoming a roadie? Is it a job where you have a “friend of a friend who knows the drummer’s girlfriend’s sister” that gets you in? How much do roadies make anyway?
I’m not looking for a change in careers or anything, but I was curious.
Check out Roadie.net for the SD. Basically, start out working your local scene and make contacts there. Then you move up as your experience/ability/network dictate.
Salary doesn’t appear to be great (unless you hit the big time), but hey you’ve got per diems and you can sometimes “interview” the groupies for backstage passes 
My brother in law is a roadie. I can assure you that it does not pay well. Most roadies (at least those here) don’t work for particular bands, instead they usually work for the record or promotion company.
Most of it is just hard work - it’s basically a labouring job, setting up stages and lighting etc. The perks are pretty well non-existent (the groupies stuff is mostly bullshit and if it ever happens it’s to the security people).
My BIL said the thrill of working with famous rock bands wore off pretty quickly when he realised that it was a badly-paid, physically hard job that required him to work nights and weekends and that the band members didn’t ever even acknowledge their existence.
It’s also pretty unpredictable - my BIL might work every night for a month, then not get any work for weeks.