Clients ability to edit

Well, after a long holiday in Europe, I suddenly thought of something. Something so important and something I am so clueless about, I had to go Google it. How would my client be able to edit it?? I cannot assume that my dad knows about HTML, jQuery and all that stuff. I found a website introducing something called "Cushy CMS" which allows your client to edit the website easily.
http://vandelaydesign.com/blog/web-development/cushy-cms-tutorial/

http://www.cushycms.com/en

However, I havent found out yet whether it allows you to upload photos yet. I'll have to try it out soon. I am worried about my jQuery photo gallery thing I thought up a long time ago. How would my client add more photos??? What happens when the space runs out???