I found the book "Mother Tongue" by Bill Bryson a good basic intro to the history of the English language and why we spell and speak like we do.
Cant remember all the details, but one of the "problems" is that the English language has evolved and developed from a whole mish mash of other languages.
It is a mixture of Latin, plus the Anglo Saxons (Germans), the Normans (French), the Vikings (Norse), and many others.
When the Normans invaded much of the legal and official language of the UK became based on French , but the peasants continued to speak in a language based on Anglo Saxon.
And of course before the days of mass communication and travel language (and spelling) developed differently in different parts of the country. In Shakespeare's time a person London may not understand a person from say Sussex (and vice versa).
Eventually of course the whole thing "merged" to become English as we know it today, but the "problems" with English come down to its strange history and development.
http://www.amazon.co....-Bryson/dp/014014305X