I've just blogged on the same suject..
i don't just read knitting blogs (but mostly)
i like short easy to read paragraphs (and blog that are clogged with LONG endless paragraphs don't get read often)
I like photo's (of progress, of yarn, of FO, of anything (even a gratuitus sunset is better than nothing!)
I like thought and philosophies. (not just what is being knit, but why!)
I dislike post about cute cats, or cuddly dogs.. (once is while is ok, but pets are not an deep interest of mine)
babies are fun.. but even they are less interesting when i really don't know them, (or their parents).
Food is OK (again, i don't really read food blogs, but a recipe once or twice a month, or a food post as often,--is ok.
I like tutorials.. (i don't always learn stuff, but i like to learn how others explain!)