This is a guide for both non-members and members that want to reach 99 woodcutting as fast as possible.
Introduction: Woodcutting is a great skill which all Runescapers can enjoy. This skill gives you the ablity to cut down trees using a woodcutting axe, which Runescape refers to as, a "Hatchet." Woodcutting is very simple, all you need is a hatchet equipped or sitting in your inventory and then you just need to click on a tree. Your player chops the tree to obtain a type of log, depending on the tree you chop. The higher you woodcutting level, the faster you chop logs, the stronger hatchet you can use and the better tree you can chop.

Forewarning: This guide is designed for those who want to reach 99 woodcutting at a reasonably quick pace, not for those that want to reach it slowly, while making money. This is for quick experience, not for money making. You will need one thing above all other personal attributes to complete this journy, that is patiences, and lots of it. So, let's begin.

1-21: This step will be the easiest step in you woodcutting career. To start, go north of the Varrock West Bank which is also located south of the Grand Exchange. I recommend wearing only your bronze woodcutting hatchet which was given to you on tutorial island so that you conserve your running energy. You need only 5,018 experience to reach level 21 and each log chopped gives you 25 experience. You will need to cut approximately 200 logs (Actually 201, but you cut one on tutorial island) to reach level 21. Bank these logs north or south at any of the banks. Please remember that at level 5 change to steel, at level 11 change to black and at level 21 change to mithril. To save money, I recommend just to buy an iron hatchet at the start, then swap to mithril at 21, to adamantite at 31 and finally to rune at level 41.

22-41: You can cut oaks at level 15 and cut willows at only 30, not 41! Why not do them straight away to save time by getting extra experience from them? The reason you should wait a few more levels is that at the very first few levels of a new tree it is extremely slow. You will actually get more experince cutting frequent, faster less experence logs than slower, and I mean much slower slightly more experience giving logs. Now actually on to the woodcutting. Move south of where you were cutting regular trees before. There will be three oak trees west of Varrock West Bank. Cut these logs and bank them in Varrock West Bank until level 41 woodcutting. You will need 36,153 experience to reach level 41, oaks give 37.5 experience each so you will need to cut (Recommended to bank aswell, like all logs, espeacially willows) 965 oak logs. At level 31, switch to adamantite and at level 41 switch to rune.

42-99: This is the final, and by far the most extreme part of your journy to 99 woodcutting. You will need a massive 12,998,902 experience to reach 99 woodcutting. This is a stagerring 192,428 willow logs as they give you 67.5 experience each. You need to head south to the city of Draynor, commonly refered to as the "City Of Willows." It has five willow trees right next to a bank so it is amazingly faster to bank the willow logs than it is to drop them. The only problem there is it that these trees, at any member or non-member world will always have people there cutting at them.

Final Notes: These are some final notes you should know on woodcutting in general.

At level 61, you have the option, as a member to upgrade to a dragon axe. If the 1.6 mill (May, 2009) is ok with you go ahead, if not, don't worry on missing out THAT much, it's not that much faster anyway.Keeping the logs is an excellent idea as they can be useful in leveling firemaking, fletching or even selling them makes quite a bit.
If you cut to 99 woodcutting and keep all your logs, you have enough to firemake to 99. Keep that in mind.
Patience is the key, without it, you may as well give it up straight away if you are going for 99.
Do it in chunks, don't kill yourself in one go. Reach level 50, take a break and do some combat training or something, then have another small break at 60, then at 70, 75, 80, 85, 90, 95, 99. If you stay consistant, you will have the will to keep going.
At 95, members have the ability to cut maples at a decent rate. You can cut them north of Seer's Village. The change of scenary might do you good.
Remember, this guide is not just used to reach 99, it can assist you if you want to reach any goal. 85 is a good goal if your not looking for 99. Having 85 woodcutting makes you an excellent woodcutter.
Happy Woodcutting!!! :)