Be different, honest, informative
Your company blog is a platform to highlight what makes your rental operation special. Here are some blog post topics that come to mind if I were posting to your blog:
Share stories that highlight interesting customer service experiences. Share your unique ability to resolve problems and satisfy customer demands.
Share times that things went wrong and what you learned from them. Sometimes I get bored with hearing about how well things go. Tell me about some times when you messed up and how you made them right. These tales get my attention.
Discuss specialized solutions your company provides the industry. I love hearing out-of-the-box solutions to complex situations. If your firm has innovated, tell the world! If you think the competition won't find out eventually, think twice. Share with the industry.
Mention specials or other unique promotions your company is offering. A blog is not merely a site for your electronic sales pitches, but it can be a place to strategically share your specials. If you offer your clientele something they need, they'll likely forward the deal to their friends.