I'm a software developer, not a designer, but I'm being forced to design websites.
In the past, I designed "by hand", never using anyone of these before. Now, I have found that there are a lot of CSS framewoks. I want to give a try to some of these, but I don't know where to begin and I don't want to waste my time.
I think the most populars CSS frameworks are:
If you don't want to waste your time, I really wouldn't recommend any of them. If you're familiar enough with CSS, it's easier to write your own rather than using a framework. With a framework, you'll be forced into learning and using their naming conventions and you'll also potentially include a lot of code that you simply don't need every time. If you need to use anything, I'd recommend using a good CSS reset rule over a full CSS framework. Barring that, spend your time learning CSS in more depth; it'll be a better investment with greater rewards in the future as you'll know why things work in addition to being able to do the work.