I suggest starting with my own Meta Guide webpage, “100 Best Yahoo Pipes Videos” [1], which is actually only 62x at the moment. I also have articles, books and example pipes listed under “Best Twitter Bot Pipes” [2].
[1] http://www.meta-guide.com/home/about/videography/100-best-yahoo-pipes-videos
[2] http://www.meta-guide.com/home/twitterbots/best-twitter-bot-pipes