Step 1: Choose a video to upload!
The interface is super easy to use now, considering an IT noob like me can do it too! :)
Step 2: Look at the top left corner, click HTML to change the width to 500 and height to 304 (note: you have to change the numbers twice). Erm I'm not sure how to show pictures anymore so just figure it out yourself... and VIOLA! you have the perfect video size for the blog! Here's one for you to enjoy..