does anyone know any Web Design software that lets you integrate a CMS into website's you build? or create an online login page so people can edit the website online.
Pretty any much CMS worth its salt will let you do that. Though to be honest, you'd integrate the Web site into the CMS, not the other way around. Oh wait, you said software. You'd have to know how the CMS works in order to do that, but it should be possible if you know what you're doing, but you're still going to have to get your hands dirty with the code (which defeats the purpose of "design software"). Why are you looking for "design software" anyway when the code it produces is worse than the garbage spewed forth by politicians on a daily basis anyway?
you can create a content management system with Dreamweaver, but you'd have to already know a good deal about php/sql, asp, or CFM. Basically you can can create a database with different fields, log into it via dreamweaver, and start using the built in tools to make forms where people can add records, modify records, log in, log out etc... It is not for newbie level, but you don't have to be a genius either...you just have to have a decent grasp of whatever language you are using and use the built in tools. not saying I recommend it, just saying I know that it is doable.