I have been looking around for battle reports, and army lists and general tactics for wood elves and have failed to find that much. I really like the idea of a bunch of tree people in my wood elf army, so I would like to include atleast one unit of each type, this includes treekin.

I dont see many people using treekin, are they not to good?

I am also very new to wood elves, as I have not played a game with them yet.
I like the whol idea of a long range army, as my only other armies are Vampire Counts, Chaos Dwarves, and A troll army i just made using the troll king from the Warriors of chaos army.

I use treekin nearly every battle. They are very resiliant and great for taking charges (especially with a BSB nearby).

Opponents of WE tend to get frustrated by the Fast fluid nature of the army. By deplying treeking, it gives them something to focus on and tends to set the battle lines of the game (e.g. they will point their big ranked up units right at them, figuring they can pin them into combat). Which helps you as well by giving you opportunities to flank and outmanouver.

I think treekin are faily common these days, they function well in the context of the new army books due to their high toughness and decent saves. People tend to use 4, if you can afford it. I tend to use 3 + a champion.

My 4 Treekin occupy a place in my heart right beside my Wardancer Highborn, Treeman, Alter Kindreds, Dryads and Great Eagle. I hold them in as high a regard as anything else in the Wood Elf list.

Ender is absolutely right. I deploy mine right in the middle, usually sooner rather than later, and they always end up right in the middle of the fight. I like to set them up slightly off center on my weighted flank with a Treeman beside them. Say I move them 9" first turn and my Treeman the full 10". This means that anything wanted to get into combat with one will get the other in the flank, this makes for a potent fulcrum for your battle line.

Once I played a Forest Spirit list with 3 x 4 Treekin, it was absolutely the most terrifying battle line I've ever seen. You can hit Treekin with a lot, but with high toughness, Armour and a Ward, Its very hard to break them on the charge, especially with a BSB. And with 12 st 5 attacks they'll hit harder than a Treeman any day.

Treekin are useful, and you'll probably use them at least a few times. I wouldn't say they're completely imprescindible, though.

Good points:
They are very tough, and can dish damage and stand punishment. Against units with low static resolution, such as chariots or most heavy cavalry, they're excelent.
They give your opponent an (usually false) impression of something he can engage, as Ender says, and you can use this to your advantage. Deception is a good weapon in the wood elf arsenal.

Bad points:
They are quite slow and rigid in an army which emphasizes maneouverability.
The models are quite bad in an otherwise excelent line. Of course, the treeman has as bad a model as them, and that's not stopping him from making it into the lists of most people.

If you're using them (and if you like them, there's no reason not to), a unit of 3 gives you a good support unit, a unit of 4 can work alone (although, as with anything else in the WE army, they'll be better with support).

*EDIT: Ooops. I forgot.
If you are looking for a general tactical advice, make sure ou don't miss reading Machiara's articles. Actually, read also the rest

And I find hard to believe you didn't find reports here at the Glade of Woe.
If you want more, I think Warseer has a subforum just for reports, there should be at least a couple of wood elf related reports there.*

I've been play testing 4 Treekins as a substitute for my Treeman and they have performed pretty well so far. Don't get me wrong they are not as versatile as a Treeman but they can sustain a lot of damage and ditch a lot of hurt in return. I still have to try out Treeman - kin tag team as I believe they would be very strong.

They are a very good option if they are supported with flankers.