Well as a new vendor here, I learned several ways.
1) Google & Youtube
Much of the information is out there, but its not all in one place or tutorial.
2) Questions, questions,
Pestering people both here and at rendo - on the whole, if you ask nicely, people are helpful and will often give you the answers you need.
3) Paigerism saves time.
When in doubt, pick apart files of products you have purchased, you can examine everything from Topology to how a Pz2s has been edited.
4) trial and error
As for tutorial making, Im not concerned about competition, but I dotn want to get ahead of myself, im still learning and right now Im having too much fun using my newly aquired knowledge to actually create stuff….