I've brewed a couple of beers from Brewer's Best kits and I was just wondering, do the grains come pre-crushed or should I have crushed them before seeping?
They should 100% of the time be pre-crushed in a Brewer's Best kit. If you order a kit from one of the other online vendors, they are typically precrushed by default, but they offer the option to request uncrushed in case you have a mill and want to freshly crush yourself.
Either way, you always steep crushed grains, if you steep them without crushing them, you aren't really accomplishing anything.