I am creating a websites for mobile phone tests. Users can post their own tests and combine it with an existing rating of each product.

I do only front-end development and I have no idea about back-end - php, sql, etc. I am not sure I should operate the website without this knowledge but my first thought is to get a professional whom I would give my website to, so that he can do the rest. Only thing is that I need to update it regularly and post my own tests. I don't know how that works and how I should approach this. My understanding is that, after I have finished the website (written in HTML, CSS, JavaScript/jQuery), I would go and find a php programmer and tell me to put it online, make it secure, make sure that the open-source facility (users post their own tests) and that it runs smoothly with the host/server I've chosen.

Could you tell me if my approach makes sense (is that the way how to do it)? What should I consider when searching the right back-end developer concerning the right price performance, trust, etc. ?