I learned nearly all the cading spots on the classic maps (high school, roy, panic v2, etc) from following around IBIS 31337's back then.
The thing about back then though was that you could help people more often (leaving a cade open a bit longer so someone could get in, or other things like that) because the admins dealt with things more seriously. The windows on the cliffside house on roy highway for example, if you were telling someone not to get near them, then they did, and got tagged after being told not to do whatever it was that got them tagged, they were booted.
Now if you try and help someone, it almost always results in your death, so the only way noobs learn spots is to either get lucky and spawn next to someone to follow, gang up and go to the spot where the last survivors were the previous round (almost always ends up being the general area of the zombie spawn), or just to use trial and error. But when they're forced to use the last option they usually just break the rules and cade break to get in somewhere.
"An Air Force A-10 Thunderbolt II flew a show of force and expended flares for emphasis over Salerno after enemy forces attacked a coalition forward base. The arrival of the aircraft prompted an immediate retreat by enemy personnel."