The usual best practices apply as they do for all content marketing:
Who is your target?
What information needs do they have in the intersection of their jobs and your offerings?
Do they show an affinity for consuming information as video rather than written content?
Where in the engagement cycle would the video fit?
This will depend somewhat on your target personas and how they tend to consume their information.
But it will also depend on the material. Ask yourself, do audio and moving pictures enhance the information transfer? Or maybe you have an interview with an expert personality. (Consider that many will tune in for an interview with, say, Mark Zuckerberg, even if the information would have been "better" as a written piece.)
Essentially, is there value in the video presentation of your content over written text or an infographic.
Goals. Always Goals.
What are your goals, at the highest level? New leads? Re-enforcing buying decisions? Making users more successful? Launching a new product?
Know your goal, and then you can decide what type of video will best fit the objective.
Types of Videos
Informational videos give relevant useful information about a topic. Examples include product demos, case studies, industry event coverage, management messages.
Educational videos such as how-tos or technology lectures.
Entertainment videos are, well, entertaining! Examples include Buyral, Kittywood and the annual Google April fools (my favorite, Gmail Motion).
Of course, any video is going to have an element of each: information, education and entertainment. But the purpose and major style elements will generally be driven by one need.
Make your videos discover-able and share-able; have a promotions plan. Use the right keywords in the titles, descriptions and tags. Don't forget to namedrop customers, products, technologies and notable personalities in the video.
Blog about the topic and embed or link to the video. Share the link with posts on Twitter, Facebook, LinkedIn, Google+ and your social media networks of choice. Distribute the link to employees, especially sales and customer support, to include in email footers and in communication with prospects and customers.
Don't forget to have a call to action where it makes sense. Even an educational video can serve up whitepapers or an ebook with more detail on the topic.
More generally, optimize your YouTube channel for the right look and feel in-line with your brand. And keep the content fresh--if you commit to making videos, plan to make more than one a year!