Another way to produce consistent blog content is to choose a theme for t he month, and focus on topics within that theme. You can then plan content for the forthcoming four weeks, or even the whole year. As you can see, my theme for this month is blogging tips.
If you have a small team of people then look at some software such as Passle.net, which is a fantastic tool that lets you and your team collate ideas for future blogs.
How do you decide what to blog about?