They don’t just find it, they write it 😉
Ah, you mean: Get the ideas on what to write?
– News (your own perspective on …)
– other blogs (RSS 😉 ) (adding, contradicting, expanding, summarizing, …)- aggregators (Digg, etc.)
– conversations- things heard or overheard- conversations- questions they get (on Quora, Linkedin etc. ;))
– their own business (like a series of tipps)
– analyzing readers / customers interests
– analysing their serverlogs (search terms)
I usually say:You are not a blogger if you have a blog. You are a blogger when you percieve everything around you as potential content for your blog(s).