I started my website 8 years ago and made it my full-time job about 3 years ago doing exactly what you've said, though without having any plan of action from the beginning.
I've talked to a lot of bloggers in two specific niches and they almost all say the same thing. They started their site for fun / something to do / be helpful and soon enough started getting traffic and started making money. None have a tech background or anything like they - they just got a Wordpress site and theme and started writing.
