um, burn logs I guess? Mostly you might want to burn outside a bank or something, so you can get logs quick and burn them again. Burning at the Grand Exchange is a good idea if you are buying your logs, which is better than cutting your logs. To get to 99 Firemaking is pretty easy since you don't really need anything and the achievement cape looks awesome. Maybe take up to 2 months max. Depending on the time you play.