Have a youtube account first of all. Without it you cant upload. The upload button is located near the top right of the main page.
Second record a video. My videos are automatically put into a a documents/DFO folder. I use windows Vista so yours may differ. You will want to rename the video as youtube will use it for the video title.
Log into your youtube account and choose upload. And choose the option to upload a video stored on your PC. Choose the DFO video of choice.
Next you can apply tags to ur video so people can search for it (DFO, PvP , Dungeon fighter , Blade master etc.)
If you want to share the video with us on the forums the super easy way to do it is simply to watch your video. Copy the web address from your browser and post it here for us.
To embed it so it can be played from the forum itself as I had done with the Me/Hallow harassment fun. You will want to click the little filmstrip button at the top of any post entry your making and choose youtube. It will send you to the site. Log in if you must and go to the videos page. Just under the video on the right side is a button that says <Embed> Click that and it will give you a chunk of code to copy and paste into the forum.
NOTES* I noticed that if you choose to embed the video that is the only thing you can post. you cannot write before or after the video. And only one video can be applied to a post. So use your post title to give us an idea of what to expect.
Hope this helps. You can ask for anything left unclear or simply ask me in game.