I am planning to release short and basic videos on youtube. I would like to have a more polished look and feel so I am wondering if there are templates that you can use with, say, adobe premiere, that are complete with graphics, sounds, etc. Sorta like how a theme works with Wordpress.
Take a look at http://www.premierepro.net where I'm sharing some project templates. If more people share their own templates there, it will become a great resource for free Premiere Pro templates. Everything you see on http://www.premierepro.net is free for both commercial and private use, and you can even download free sample chapters from the book "The Cool Stuff in Premiere Pro".
Video Hive has several professional assets with various degrees of specificity that you can integrate to your project for a reasonable price.
There are many companies which participate in the production of the templates of the video production. Our company provide better facilities than any other company to produce templates as well as audios and videos also. You will get all the facilities in one place.