There are a wide variety of approaches to heroquesting: which is as it should be. Some people use them rarely if at all, some people use for everything (want to defeat a foe? Do "the Hill of Gold" and make them Chaos. Want to steal something? do "The Sandals of Darkness". Chief disagrees with you? Do "Ernalda Persuades the King" And so on!
Sources for heroquesting can be hard to find, but you could do a lot worse than"Blood of Orlanth" which culminates in one.
A heroquest can provide a whole chain of scenarios in the preparation too. The power of a heroquest is expended in bringing this world and the otherworld together, and in the resulting connection between them, ie the effect or result. The more power spent on bringing the two worlds together, the less there is in the result. Therefore, the more similar the two worlds are to start with, the more powerful the result. Hence the advantages of costumes, items and, most of all, people.
This last is the most interesting: Heroquests are most powerful when the gods (or whatever) in them are "played" by followers of those gods, and the more powerful the better. This is usually easy enough for the ones on your side, but rounding up people to represent the antagonists can be...interesting.