Joomla website implementaiton

I am currently utilizing a hosting service through register.com. I have uploaded the Joomla application, however, do not know how to use it. I have selected wallpaper/graphics from istockphoto and know the exact layout of what I want. I need your help to implement and a little guidance so I may edit the site later. Also looking to establish long term relationship as I outsource these services + to my clients.