More often than not it is preferable to embed a YouTube video into your page content, as opposed to linking off to YouTube and taking visitors away from your site, below are some tips on how to do this:
First off, it does annoy me (it really does) that the embed code that YouTube provide for each video is invalid HTML, so, here is W3C valid HTML you should use:
Note, you must use the embed URL provided by YouTube here and not the standard link.
Turn Off Related Videos
When the video has finished playing, by default it will then show you related videos. This can be an issue if, for example, the video on your website then shows related videos that link to a competitor's videos. To get around this, you simply append &rel=0 to the end of the URL:
If you want the video to start automatically playing when the page is accessed, simply append &autoplay=1 to the URL.
As an aside, if you ever want to link to a YouTube video, but want to access a video at a certain point, you can add minute and seconds parameters to do just that, so, whereas normally you'd send a link such as:
and say "watch this for the greatest free kick you're ever likely to see, but if you don't want to watch highlights of a great game then spin on to about 4m40", you can now just send the following link:
You just need to amend the minutes and seconds accordingly, it's that easy.