Blog writer for a long term project

I need a blog writer on a long term basis. I need the person to write 2 - 3 blog posts a month. Each post about 150 - 200 words. The individual would be writing for a vertical industry software, so he/she needs to get good knowledge. The material needs to good quality and should engage audience with benefits of the software, trends, features, demands, competitions etc. I need also need to see sample of your topic specific blogs or content on a specific subject with multiple samples.