Create a Website: ready Photoshop design to Dynamic website

I'm designing my very first website with photoshop, I need help creating my design into a dynamic website. I previously met face to face with a webdesigner, discussing my plans of creating my site. I'm very determined about how I want my website to look, and I don't feel like leaving the designing to anybody else. He advised me to design my website with photoshop, not only would I get my site exactly the way I wanted, but it would also make it a lot less expensive. I'm in the prosess of designing the homepage of my site, but I don't have an overview over all details the person creating the site would need. And I'm unsure if I would need split up the design and save all the small details for web, or if the webdesigner would be able to do this (and how much less would it cost me if I did it myself?). Before I can hire someone I would need to know who to hire (I don't know the title of the profession of someone who would take my design and make it into a site). I also need to know what details I need to make clear (about the design) for the person who will do this work for me.