This article might be interest to you A manual for effective online video placement
To quote the aspects of the article which might be interesting to you :
On-page video placement
Front and center: Video can be the most engaging online asset you have, so make sure consumers see it and view it. The video should be
visible when the page loads. Placing videos below the fold and
requiring consumers to scroll down will not offer any benefits to your
brand or to the consumer. In addition, the call-to-action should be
prominent, such as "Click here to view a video about..." or a "Play"
button displayed.
Maximize the play experience: Videos should play embedded on the web page or in a lightbox player. The method that you choose depends
on the type of video, target audience, and desired action. A lightbox
approach guarantees that viewers are focused only on the video by
opening a layer on top of the page that plays the video, such as the
Tiger Direct product video featured below. That said, the layer will
block access to everything else on the page, so multitaskers may not
appreciate this approach.
With regards,to the length of videos you should be looking at, I recommend looking at this article .To quote the article :
The rule of thumb I try to follow when creating internet videos is
this: stick to one idea, one topic and one main point, and say it as
briefly as possible without leaving out all of your good stuff.
Personally, I find than most of my daily news commentary videos are
between 60 to 90 seconds with some occasionally going to 2 or even
three minutes.
Also remember that you don’t have to shoot for exact, precise times
like 30 or 60 seconds. Those exact times mattered in traditional
linear broadcast venues where everything is scheduled and programmed
around a set grid. But social media and internet video isn’t like
that, so take a little more time or a little less time if that’s what
you need. If you’ve got a great message, you might be able to say
everything you need to in 9 seconds. But if you’ve produced a
world-class documentary that’s 3 hours long, you might be able to get
a huge internet audience for that too.
Another option is to break up our videos into part 1, part 2, etc.
This way people can take bite sizes without ever feeling impatient.
There is a certain psychology involved with your viewers. If you make
your videos consistently interesting and consistently short, then you
always are leaving them wanting more. However, if your viewers are
consistently dumping out of your videos before they finish, you are
conditioning them to turn you off and to make judgments that you may
be boring them. All things being equal, it’s better not to do that, so
err on the side of being just long enough to be really interesting and
not one second linger.