Why would you use a picture or other media in your post?
I recently had someone ask me this question. I told them a very thought out answer that basically lays out that it gets your point across visually, it shows something else about your post, it shows you put more time and effort into your blog. I encourage everyone to use pictures in your posts, I do it all the time on Ryan444123 dot Com, not here because most of the topics I discuss are very hard to draw together with an image.
Also, audio is awesome! There are several directories of free music availible. Including PodSafe and GarageBand. Don’t forget that you can upload audio offsite to save your bandwith, and disk space. However, anyone with a decent hosting plan can afford to hold a few audio files. Forget the podcasting plans offered by GoDaddy and the like, they are a bunch of rip-offs! Just get something with 25-50 GB disc and 100-500 GB width if you are serious about podcasting.