Frameworks

I'm not a professional by any means, but I'll give this a shot. This is a pretty broad question, and one subject to personal preference, as well as specific project needs like size, responsiveness, customization, etc.

That being said, I've used [Bootstrap](www.getbootstrap.com) on a couple projects with some success. It's great for getting up and running extremely fast, and has lots of templates and widgets. Although you can pick and choose what modules you want, it does come with a huge amount of extras that might get in your way more than you want. I often see it compared with Zurb's Foundation, although I haven't given that a shot yet, so I won't offer an opinion on that. I hear good things though.

A couple smaller frameworks I like are Layers.css, Skeleton, and Goldilocks, which I've had success with.They're purely css and very lightweight as they have less predefined styles.

Some honorable mentions from my google search are Pure, Gumby, and YUI, which all look sort of interesting.

Obviously that's a lot of information. The two I hear the most about are Bootstrap and Foundation, so you probably can't go wrong at least being familiar with them. Good luck!

Also, I just remembered that Treehouse has a Frameworks basics course here that walks you through bootstrap and foundation.