I usually record an hour or two then split up at logical places and try to keep it fairly tight. The thing I dont quite understand is when I was doing my initial research, some people would use fraps to record the vid and audacity to record the audio. Then they would sync and render and then upload. But Audacity has a reputation (from the same guy I was researching) to be unreliable so I just used fraps to record both the vid and audio. The only downside to this method is you cant independantly adjust the audio levels from the vid, so you have to make damn sure you have the game sound levels just right, you dont want to know the amount of hours I threw out
On a side note for this thread, does anyone have any weird and wonderfull methods to get into the 'headspace' for commentating? Or do all YouTubers have to be naturally self confident and slightly strange in the head ?