The best video keywords are specific (long-tail) phrases that show up in both YouTube and Google Autocomplete. This way you can rank your video in both places and get more traffic. Start typing a keyword into YouTube and it will complete the phrase, or use the underline character _ to have it fill in the blank with more ideas. You can do this anywhere in the phrase.

Have fun.  In my experiance the best bet is to upload a plain text file (no title) into the transcriptions tab. Don't worry about the time stamping the Youtube voice regonition algo is pretty good with matching the words up for CC.  Wait 3-4 minutes after you upload and you should be able to watch your video in closed caption mode to make sure that it worked right.
One thing I did not see here (was just reading up on this the other day) was the importance of how one needs to have the content just right, including title and description (backlinks to website) and all that on the FIRST upload/pass. You lose the opportunity to perhaps have your video show up in people’s Youtube home page and perhaps even get picked up and circulated more widely if you don’t do this right out of the starting gate with each video.
You can do a sitemap and include any videos on your site that are hosted on other sites (like Youtube).  However, I don't think you can submit a sitemap on behalf of another site (like Youtube).  Generally speaking Google is really good at indexing Youtube videos that are embeded on third party sites.  However, they almost always rank the Youtube version ahead of the one on your site so a sitemap probably doesn't have a huge impact.  If you are hosting with a different third party site (like vimeo or metacafe) and embeding then you might want to do the sitemap for those videos.
A video keyword research, more precisely, is what you need to do first. List down your keyword ideas as your potential keywords. Narrowing down your target keywords is like narrowing the pool of competition. Also, the proper use of the right keywords contributes to the popularity–measured in views, shares and other engagement metrics–of a particular video.
I agree with you on building backlinks to your primary user channel page.  We link to that page from our site, our blog, our press releases etc.  However, there is also value in building links to the other pages on your channel including the video pages themselves.  It is helpful to think of your Youtube channel as a microsite that passes pagerank just like any other site.  The easiest links to build are the ones from inside of Youtube (subscriptions, comments, favorites all get posted on other people's walls).  If more influential and active users engage with you they pass you more pagerank.  Likewise external links also pass pagerank to specific pages on your channel that can then flow to your other pages.
Thank you for your advice. A lot of the content (although really good) was pretty similar to other blogs on the topic. However there was one new point for me that I think is really going to help. I love the idea of adding a link to our latest piano video in the signature of all our teams emails. I can modify all of the signatures every two days when a new video is released and this will put them in front of so many more people. Great idea!!
Overall you really don't want people only viewing your video for 5-8 seconds because although the view will count and help with that ranking factor the attention/engagement on that view will be hurt and will hurt your rankings.  It makes sense.  Youtube would rather display a video that is watched all the way through 1,000 times rather than a video where 10,000 people leave after a few seconds.
Dear Brian, thank you for this clear and helpful tutorial. A question: if I want to rank a YouTube video specifically on Google… should I focus only on engagement (retention views, comments, social media shares, ecc.) or should I add also classic backlinks (anchor text to the video url, from other sites)? I still don’t understand If the last ones are almost useless or actually useful.

Reviewing cars is good if you can put it on your website and it’s useful to potential customers, otherwise yes keywords like chevy dealership o’fallen il will definitely be the ones that get you appointments. And that is local SEO which has different ranking factors (Google My Business, citations, reviews). I have a guide for WordPress local SEO in my navigation menu but most everything is the same even for non-WordPress sites.
I totally agree that CTR is significant.  However, unless you are a Youtube partner (the old school type) you don't have all that much control over the thumbnail for your video (that is why I didn't included it in the list).  For most of us mortal Youtubers or ones that don't want to monetize our channels we have to live with the couple of choices that Youtube gives us for thumbnails.
That's the content side, the stuff that you control directly. By making awesome content, you can then create awesome engagement, which is really the second part of ranking on YouTube and probably the most important. All else being equal, if you do all of these things and there's no competition, you're going to do great. But if there are other people with other videos that want to rank, and let's face it, almost any industry has other videos that want to rank for the keywords that you want to rank for, you're going to need to do more than just throw up a video with a great title tag and a description and some tags and transcription. It's kind of like creating a website but not telling anyone that it's there. So, now suddenly you have to take it to the next level. You need to get some engagement. That's the next six ranking factors that really come into YouTube. I'm just going to go quickly through them so that you can understand some of the different things that YouTube is looking for.
Number five, I put this under the content side of it, and that is your channel authority. You control your content, which means you control your authority. Google is looking for channels that have authority, and it's going to use that as a basis for your ranking. It's going to be easier for someone who consistently creates awesome video to rank for terms versus somebody who just throws up a random video. Now, it's a little bit controversial just in that YouTube also has the power to let any person with a cell phone rank really well for a video if they have enough engagement, which is what we're going to talk about in a minute. But all else equal, if you have a good channel that you have great content on and good engagement on your other videos, that's going to flow over into your current video and getting it ranked. So, you want to make sure that you look at all of your videos as a whole and your channel, not just your single video when you're trying to rank.

There is much you can do right with YouTube but there is also a lot of things you can do wrong! For instance all of my affiliate videos are on the same channel, if Google decided i violated their tos I would have to start all over but Google see the value I bring. I would suggest using different channels for different niches rather than having 1 channel or 1,000 channels.