Want to get 99 Woodcutting?Of course you do thats why you're here.
This guide will help you get there.
1)Getting an axe.First thing you need to do is get an axe that corresponds with your woodcutting level. Here is a list of axes, where to get them and what woodcutting level they require.
Bronze Axe- General store- Lvl 1 (lvl 1 Attack required to wield)
Iron Axe- General store-Lvl 1 (lvl 1 Attack required to wield)
Steel Axe- General store-Lvl 6 (lvl 5 Attack required to wield)
Mithril Axe- General store-Lvl 21 (lvl 20 Attack required to wield)
Adamant Axe- General store-Lvl 31 (lvl 30 Attack required to wield)
Rune Axe- General store-Lvl 41 (lvl 40 Attack required to wield)
Dragon Axe- General store-Lvl 61 (lvl 60 Attack required to wield)
2) TreesNext you'll need to find what trees you can cut at your level and where they are.
Regular Trees (Trees)-Required Lvl 1How to get there-Teleport to Varrock and run East out of the city then go slighty North.

Oak Trees-Required Lvl 15
Run slightly South back toward Varrock next to the gaurd tower.
Willow Trees-Required Lvl 30Teleport to either Lumbridge or Falador and run to Draynor village.
this is a good spot because of it closeness to a bank.
Maple Trees-Required Lvl 45Teleport to Camelot and run West to the bank. Right across the road are maple trees.
Yew Trees-Required Lvl 60
Magic Trees-Required Lvl 75Teleport to Camelot and follow the road West until you reach the Ranging Guild. Run behind the Guild and the trees are there.
You do not always need to bank your logs. You can always use a tinderbox and train your Firemaking or a knife and train Fletching(both knife and tinderbox can be bought at General Store).