Reference cards are concise guides you can keep handy when mastering a new skill. They are cheatsheets on steroids.

DZone produces an attractive weekly series of RefCardz, including this great two-part series on CSS web design:

Link: Core CSS: Part 1

Link: Core CSS: Part 2

The RefCardz series is geared towards developers — however these two free guides are a great resource for web designers deepening their CSS skills.

Note: DZone requires you sign up for a free account to download your guides.

Source: Long-time readers know that we love cheatsheets. Here’s another great CSS cheatsheet we wrote about two years ago.