My pleasure! I could ramble on about the End of the Han Dynasty/Three Kingdoms period in Chinese history (about 184-281 AD) for hours. I mostly got into them because of the video game maker KOEI's strategy series based on the period, but I have since dived into the history myself to understand what really happened back then in great detail.
Had I money to spend, I would certainly buy the books put out by the foremost expert on the period, Dr. Rafe Crespigny, such as Generals of the South, and To Establish Peace, which is a partial translation of one of the most useful historical sources on the period, The Zizhi Tongjian. He, and other amateur translators, have provided a great deal of information to the English-speaking world by translating these primary and secondary sources for us.
Cao Cao (pronounced T'sao T'sao), is one of my favorite historical figures. He has that kind aura of unique greatness that seems to surround all men who have profound influences on their time, like a Caesar or Napoleon. His Wikipedia page has a more complete, historically accurate representation of his biography.
Despite being a military warlord, he also was learned and scholarly. He, along with two of his sons, revolutionized Chinese poetry with his style, eventually contributing to Tang-style poetry many centuries later. He is also known for early contributions to the Shanshui poetry style.
He also knew to invest in agriculture and education, even while engaging in wars. While his primary purpose in agriculture was ensuring supplies for his troops, he also put many refugees to work cultivating wasteland and turning it into productive fields; bases and camps that were not in danger of seeing action also worked to engage in farming. Many refugees and citizens who might have otherwise starved to death were saved by his policies. In 203, once Yuan Shao, his primary rival at the time had passed, and his forces no longer a major threat, he instructed education to be promoted throughout his jurisdiction, and every county with at least 500 households was to have an official in charge of education. Young people with potential and talent were selected for schooling; this advantage of education the Kingdom of Wei had over Shu-Han and East Wu, along with other advantages, proved to be extremely useful in ensuring there were a number of intellectual, educated, and talented people to place in positions of power.
He's an extremely compelling figure, who is not easy to classify as simply "good or evil"; his actions had motivations behind them. He was extremely intelligent, ambitious, and ruthless; yet he also valued loyalty, and sought out people who were virtuous to serve for him. He relied on the people beneath him to perform well, and rewarded success and insight. He remains one of my favorite historical figures I've ever encountered.