Can you provide me with a long and well-thought-out comprehensive yet simplified guide of [SUBJECT], that only includes offline information that you are certain is true and excludes any speculation or uncertainty? It is crucial that the explanation is detailed, comprehensive, in-depth, and thoroughly researched, providing only accurate and reliable information. Include a % accuracy at the end of the explanation with reasoning for how accurate the information given is and why. Give 2 web sources with general urls (accurate as of 2021, ends in .com, .gov, or .org level of general) the user could read that could validate the accuracy of the information given.