This is a subject that many people are interested in but few understand.
There are two goals that you want to accomplish with your title.
First, you want it to be search engine friendly and be something that will be displayed in a lot of searches.
Second, and perhaps most important, you want the title to encourage people to click and read YOUR post as opposed to the other links that are presented in the search.
Check out this handful of articles to get some great ideas for blog titles from some of the best blogs.
John Chow has a good article about writing great blog titles: How To Write a Good Blog Title for High Website Traffic
Ten formulas for great titles from copyblogger: 10 Sure-Fire Headline Formulas That Work
5 tips for writing great blog titles: 5 Tips For Developing Great Post Titles for Your Blog
A list of 33 ways to write a great headline: 33 Foolproof Headline Strategies
Hope you find these ideas helpful. Remember a title that doesn't get clicked doesn't bring you any readers.