Ask HN: Good resources to learn about design, UI, UX?

I often see comments about how libre and open source applications are ugly or are poorly designed (from a human interaction perspective).

What would you (or the design team in your company) recommend reading to better address this? I'm looking for anything:

- books about general design concepts to keep in mind when building something (preferably computer software) - best practices in terms of UI/UX - good guidelines from existing projects

Thanks!