One of the problems when I embed YouTube videos into resources, is that learners end up looking at the 'related videos' which appear at the end and in some cases are taken to an inappropriate clips; is there a workaround which will disable this feature and thus remove the possibility?

There is indeed, when pasting the embed code into your post, simply add &rel=0 at the appropriate point in the embed src tag. e.g.

<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/YL3PtlxYkZ4&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/YL3PtlxYkZ4&rel=0&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>

To test the customised code has worked, play the clip at http://uk.youtube.com/watch?v=YL3PtlxYkZ4 and then the one below to see the difference.