When creating a website save all pictures in a folder before uploading them to your website - this way in case something doesn't save, you still have all your content.
Write out any text that you are going to enter into your site in a Google Doc or Word Doc and save it to your Drive, H drive, or Flash drive so that you have a copy of it as well.
Pick a simple theme, so that there is not too much content for you to change, but you also have the freedom to be creative in designing your site.