Building a Blog

What makes a good blog?  Content alone, humor, intelligent discussion, pictures or just "conversation" with people with similar interests, all of the above?  So how do I promote my thoughts and ideas, and gain an audience.  I am new here, and just feeling my way through. 

I follow several money-saving coupon blogs, which are great, but I don't want to be a copy-cat of anyone else's efforts.  I just post my finds, successes and disappointments.  I like good food and wine, so occasionally, I'll post a recipe or talk about a winery visit.

Other interests include environment, such as recycling, and charitable causes, such as the Food Bank and abused women's shelters.  I have posted briefly on these topics, but there is so much more to these services than just putting your recycles out every week, and dropping a box of cereal into the collection boxes.

I'd thought to be (or become) a source of area information on events such as wine and food festivals, family fun, outdoor events, local concerts, etc.

Is this too broad?  If so, how do I go about narrowing it down, and still having interesting, readable content?  Where do I go from here?  I need to find my niche...