Sabine,
If you haven't worked with a VBulletin type board before it can take some time to get used to, even for the best of us. There are still some features in here I don't know how to use!
1) I think you're referring to posting a "new thread" and to do that you'll see a blue button on the top and bottom of the left side which says "New Thread" and looks like:
http://www.mychinamoto.com/forums/im.../newthread.gif
2) To pos youtube videos, take the video identifier for you video which is all the numbers and letters after the "=" sign in the URL. In your case it's : xo-RAG6cLwc
In a post, highlight the "xo-RAG6cLwc" with a click and drag of your mouse and then click on the "Wrap [YOUTUBE] tage around selected text" button above. To see if it work properly you can click "Preview post" below the editing window.
When done it should look like:
3) No sure what you mean by the editor button? There is a button in each of your posts which says "Edit" that allows you to edit your own posts. Looks like:
http://www.mychinamoto.com/forums/im...ttons/edit.gif
Hope this has helped!
CC