How to
Some guides are for the field, like the Golden Guides, and others made to help others understand a topic, like a guide on Nuclear Science. The reader cannot observe the reactions but can understand how they happen. How to guides are mostly populated by field guides, like "How to fire a gun properly." and "How to be a helpful Wikipedia contributor". Guides can't start without the "how to" prefix, in the process confusing potential readers and making the title seem like a statement rather than a question-statement hybrid. "Fire a gun properly" sounds like a statement, so people will click away from the guide without actually understanding how, just planning to do what the title said.