Just in general, could be useful to say: there are 2 (or 3 or more) stages in website building: Design and Launch. After you've done it, got your payments for it,All other work on the website, such as: improving, editing,updating - is actually website maintenance. So in fact again - will be helpful to have a plan beforehand with all these stages being explained to the client thus he will be aware at all times on what stage the project is.