anything with oak planks is good for construction, but once you can make the second fireplace, use limestone and continue to make those, they are the cheapest way. But cutting oak and making planks is the fastest, cheap, way of leveling. To level herblore, just go to the chaos druids in the wild under edgeville. youll get lots of herbs there. and normally no one pk's anyone there, because its easy to run and its like lvl 3 wild.