Use Photobucket.com is the easiest way. after you upload your video to photobucket you will see an "Image code" link under your video. Click on that one. It will copy that. Then goto snowest to your post. then right click and select Paste. You will see a mess of numbers letters. Don't worry! Then just click preview to see if it worked before you post it. If you have any other questions shoot me a Pm.
Later
Good Luck
The good thing about Photobucket is that it will let you upload a video file up to 100MB.