Having sat through many, many , many (do you get the picture) speeches by the best man at a wedding, some good and some bad, I thought it would be of use to round up some helpful links to articles that tackle this potentially very stressful experience. I hope they will be useful to you or anyone you know that needs to give a speech as the best man…good luck!!
http://artofmanliness.com/2008/07/22/how-to-write-deliver-good-best-man-speech/
http://www.wikihow.com/Write-a-Best-Man%27s-Speech
http://www.thebestmanspeech.com/
http://www.bestmanspeechinsight.com/how-to-prepare-for-a-best-man-speech.html