The Upwork hiring headquarters https://www.upwork.com/hiring/category/for-clients/
You might find related articles on HR/recruiting blogs but not many/if any specifically oriented on the subject, such as theundercoverrecruiter.com
You might also have some luck searching Google. Now I realize your not in the US, so my suggestion MIGHT not work in your version, or if you are using Google - your country. Just trying not to assume.
However, I came across a slew of "blog articles" a few weeks back, and out of a general desire to learn, did some further research with specific keywords. Lots of content about this on a lot of US "running a business" type sites such as www.entrepreneur.com. Examples:
how to hire a freelancer project manager
how to hire a lead gen freelancer
how to hire a general va freelancer
how to hire a graphic designer freelancer
best practices for hiring a freelancer project manager
best practices for hiring a lead gen freelancer
best practices for hiring a general va freelancer
best practices for hiring a graphic designer freelancer
etc etc etc
Most searches after that begain showing the same or similiar results.