That really depends on the type of logs. It also depends on your current level. I suggest you use a skill calculator - you can search for one online.
2,114 Maple logs ( making maple longbows )4,227 Maple logs ( making maple longbows (u) )
I would recommend using a skill calculate from a trusted Runescape guide site. I have provided you some links below in the "Related Links" section.
it all depends on what level you start at go to http:/www.tip.it/runescape/?page=firemaking_calc.htm and put in your current xp and it will tell you an exact number
89,197.
It would take exactly 2555 willow logs.
One maple log on RuneScape will grant you 135 Firemaking experience when burned. You need 11,824,010 experience points to advance from level 75 to level 99 in a skill. 11,824,010 divided by 135 equals 87,585.25926.Therefore, you will need to burn 87,586 maple logs to advance from level 75 to level 99 in Firemaking (assuming you receive no experience bonuses).
What skill are you refering to exactly try making your next question easier to understand.
there are many places but if yiu really want to find them it would be in lumbrage or varrack
It depends on the size of the fire pit and the size of the logs. Typically, you can burn 2-4 logs at a time in a standard-sized fire pit. It's important not to overload the pit to prevent the fire from getting out of control.
144, 679 willow logs, which equals to 2,025,506 GP if you want to buy them all.
you would have to burn 96,551 maple logs and you need 13,034,366 experience to go. Hope this helped.
1,187 - making willow short-bow's (u), may require less if you change to willow longbows (u) when you get to 40 fletching.