100 years after the originals left a new tree grew. The sign that was going to be used for the new wckery bridge sign was made out of that new tree. 

yes and they made a few stake to kill klaus but klaus found it out and tortured damon and stefan gave him all the stakes? thats what i remember, but i cant remember what happened after??!

Afterwards Klaus burned the stakes but there was still one left. Dark Alaric had the last one and hid it then Esther infused the magic in the ring with the stake.

Yep, the "Original" Alaric had it till he died.  Then Damon took it from him and hid it away in a safe place that no one would find but him and I assume he let Stefan know where it was, but that's it (I'm guessing).

But, that no longer matters since Stefan being the epic fail that he is, literally gave that stake--their ONLY weapon against the originals at this point, as they don't even have a white-ash dagger--to Rebecca.  Then Rebecca being the epic fail that she is, literally handed the stake over to Kol.  I imagine in two weeks Elijah will have it and somebody might be dead (this is a random guess for fun, based on no real evidence from the show...).

Really though, why in the hell did Stefan even bring the thing, to threaten her after he overpowers her...how, with Caroline's help (bad writing to tell you the truth; I mean he gives the stake to Caroline AND they split up, WTF)?  So stupid.  So I guess Kol has a reason to be on the show now...

Kol got it where ever damon had hid it. All he would have to do is search the house until he found where it was hidden. Ester spelled it with a gilbert ring to protect it from being destoryed when used.

No, you need to watch the last episode again.  Although I do think I got some of the events wrong, like Kol taking it from Rebekah.

Stefan brought the white oak stake with him; Caroline had it while scoping out the second floor.  Then I assume Rebekah had it after she captured both Caroline and Stefan and took them to the library (though I'm not sure that I actually saw Rebekah with it, making the scenario below more likely).  Then later Kol pulls the white oak stake out in front of Rebekah, which makes Rebekah ask out loud how he got his hands on it (from her, I thought; but, that may've been the first time she saw it at all).  He obviously stole it off of Rebekah (again this is a "maybe"), maybe when they were interrogating Professor Shane (as they were close together).

Although it MAY be possible--and more likely--that Kol in fact was on the second floor to begin with, so he didn't steal the stake at all from Rebekah, he just took it away from Caroline.  I'll have to watch that sequence again, but that may in fact be the correct line up of the events.

yeah, thats it, i remember now, thanks.