To upload a replay you do the following:
> Click go advanced below your post
> Click "manage attachments"
> click "choose file"
> Then you need to find wherever you've saved toribash to, for me it's in the :C drive under games
> Find the replay
> Wait for it to upload (usually a few seconds)
> Post
To upload video you can just put it on Youtube and then copy the numbers/letters after the "=" sign on a youtube view url and paste them between these tags:
[YOUTUBE.][/YOUTUBE.]
but obviously without the full stops.
Hope that helps.