Go to mypetpeeves.com/create/rant, or click on the “Post a Rant” link that’s shown on every page to logged in users. Just fill out the form and click the "Save" button at the bottom of the page. That's all there is to it!
That will let you submit a standard Rant, but if you want to submit a Video Rant, you'll need to click on the "Create Video Rant" tab. That form includes a field where you can paste in the link to your video, but otherwise the procedure is the same.