Simple Wordpress site designer

We're looking for someone to assist our main site developer, however, he has been busy with other tasks for us.

We mostly just need someone who will know how to customize Worpdress sites themes and have a bit of knowledge in html and css, with some instructions from our developer to start out, as we wish to build out multiple sites in bulk.

Because we just want to many simple sites, this will mostly be a job to build quantity over quality. 2-3 sites per day should be normal.