i'm like a total newbie to this too. i didnt compete last year and just got assigned it. what is it like? and no one knock me, i dont have the rulebooks or any supplies yet bcuz we just got them ordered. :/
I'm new to this too. However, with some studying on the Crime Busters Wiki you should do fine. For your powders, liquids, and metals, you should ask your team coordinator for these supplies. You need a lot of stuff (as in the rulebook) to succeed in the competition.
Beforehand, you should be able to tell sand and yeast apart from all of the other powders, as well as find other surefire methods to quickly identify each item in question. Also, study fingerprints, chromos, and other stuff you find on the Wiki.
Basically, for SCB B, all you are given a crime and you have to analyze the items at the crime scene and write an essay about the verdict in about an hour. You work in groups of two, and must know about a lot of stuff that's on the Wiki. You must determine many powders, polymers, fibers, etc., try to get your event supervisor to get these to practice with. It's relatively simple, but find a way to fully utilize your time.
Hope that helps!