You need to choose where you want to upload and publish your podcast, this could be just for classroom use where your podcast is shown on a monitor or touchscreen, added to the school server so that it can be viewed anywhere in school, loaded onto the school website or uploaded to a public site, such as Youtube, where podcasts can be viewed by the public or selected groups, such as parents.
In your classroom students can view the podcast on a laptop or PC monitor or connect the computer to a large wall mounted screen
Publishing online is perhaps the most technical part of the entire process.
To view on the school network you need to upload your MP4 podcast to the school server
To view online you need access to a web server. Copy the MP4 file to the server. The podcast needs a web page and an RSS feed. For the web page, use your favorite HTML editor (like Dreamweaver or FrontPage) or put the podcast information into a blog posting.