Then I also recommend people read "The Non-Designer's Design Book," by Robin Williams. It covers the basic principles of page layout, which are also the same basic principles of screen layout: presenting the most important information as best as possible and getting rid of everything else.
Good UI design is good design first, and UI-specific second.
Design is also not art: design has testable goals, has a specific purpose, to get someone to understand something, to help them execute a task. You have to test your UIs with actual users and then update them based on the feedback you receive. Book like "Designing for Interaction" or "Sketching the User Experience" will include parts about getting good information up front, and then validating the UI you've designed after (or you can get more pragmatic and read "Interviewing Users" and then "Remote Research" which will leave out the "how to design the UI" bit in the middle).
At some point, you will need to get into the visual design of your UIs. I can't help you with this so much; I stay mostly on the research and high-level design side. But, David Kadavy's "Design for Hackers" seems to get around okay, so that might be a good start.
This other comment by ctbeiser also has some good recommendations from a different perspective: https://news.ycombinator.com/item?id=5199409