To grab the file from YouTube I use 'Flash Video Capture' which an be purchased from:
Go to YouTube and start playing the video you need, grab the URL and paste it into the ADD screen in the application. Add the following to end of the UR:
Hit the download button. It will grab the video for you at that point and place it where every you set the output to.
Some videos download as .MP4 and at that point I'm good because the videos are ready to be placed in my 'My Videos' folder. However, some files download as .FLV and I need to convert. I use 'FFmpeg' as it is the best command line conversion tool I can find, I use this syntax:
ffmpeg -i "c:\MyVideo.flv" -sameq -ar 22050 "c:\MyNewVideo.mp4"
The -i is for input, the -sameq means 'same quality' and the -ar is the audio sampling rate which should be set to twice the source (22050) for CD quality. You can read the complete syntax and download the tool here: