Just wanted to make a recommendation for Richard Parker's guides.
Richard is a very experienced business buyer. He maintains the blog at bizquest.
His own sites are
He sells guides there on buying businesses and buying internet businesses. His guides are the only ones recommended by big business broking sites such as businessesforsale.com. But there is also a lot of good free information on his sites and the blog above.
Some of you very experienced buyers may find that Richard's internet business buying guide could do with some updating (I may work with him on that at some point) but I'd say they are still worth the read.
Richard is a good friend of mine. If you've read his stuff and have a question you'd like him to answer, start a thread or drop me a PM.