CSS frameworks
You are neither graphic nor ergonomist and you still want to make a website or web application with a mobile version which is not too bad and such without you smash head? Several projects exist to make your life easier. Y'll need of course to have some understanding of HTML or you will very quickly break your teeth. Each of the frameworks I'll talk about is popular, maintained, scalable, documented and above all free and open source, so you can enjoy your community improvements or make your own version in a separate branch. These frameworks also have a rather strong dependence with HTML5 and CSS3.
Foundation
This framework is very simple to learn, you just download the CSS and HTML into your page and you have already realized the more complicated. For the rest you can simply refer to the documentation so as to affect the right class at the right element. It is possible to integrate JavaScript modules, without additional code will add functionality to certain elements but the framework can work without. Now, if in the mind of the programmer you live, it will be possible to recover not the CSS version but its Foundation Sass code. Sass means "syntactically Awesome Style Sheets" it is a programming language that generates CSS.
Bootstrap
Created by two developers twitter, this framework combines learning simplicity and compatibility bluffing. Documentation is huge and active community. Bootstrap side code is available in CSS but also LESS and Sass giving you a wide choice of technology. Again the JavaScript part is not necessary, but adds a lot of very nice things like modal windows, tabs, tooltip and many others.
Customization
When I told you it was all baked, I lied a little, because if you use a CSS quite ready, your site / application will look like or even be the same as your neighbor. To avoid this it is possible to customize your version of the framework, in bootstrap there is an interface to change the colors and set some parameters. For Foundation, there is also a much simpler interface to get to the point.
Conclusion
Both frameworks are in pretty much the same thing, the only real change will be at the level of classes that you will use. For my part I have used both and I must admit a slight preference for Bootstrap.
You will find all the necessary references to start here: