This Is Responsive | Tips, Resources and Patterns for Responsive Web Design
Patterns, resources and news for creating responsive web experiences
A Selection Of Web Apps That A Web Designer Should Know About
The Grid System
The grid system is an aid, not a guarantee. It permits a number of possible uses and each designer can look for a solution appropriate to his personal style. But one must learn how to use the grid; it is an art that requires practice.
Gridulator: Make pixel grids, lickety-split
Tell Gridulator your layout width and the number of columns you want, and it’ll spit back all the possible grids that have nice, round integers
Ultimate List of HTML5 and CSS3 Tools | Admix Web
great tools that can help you to master these new features of both HTML5 and CSS3