Don't have any good resources unfortunately but I've seen my share of UI/UX people who are plenty good at creating "beautiful" UIs which end up being giant unusable pieces of crap. So I would place a whole lot of emphasis on understanding the user first. What kind of device will the user be interacting with your UI on? Where will they be? What does their existing workflow look like? Some of this overlaps with the field of human factors and ergonomics, which very few in the industry have even heard of.
I would also include a chapter on accessibility. I've been unfortunate enough to have worked with UI people who genuinely didn't give a crap about it. And they'd even get defensive about stuff around colour blindness, attempting to justify their bad choices through poorly made assumptions about the end user (see paragraph one). That's just one small part. I could rant and rave for hours about screen readers, the size of text and fonts.
I was so intimidated by the WCAG guidelines, but after a while I realized that A encodes “don’t make your app a steaming pile” and AA encodes “don’t make your app a steaming pile, plus 4-5 extra accessibility related tweaks”
Depends on the context. But if for example you aim to replace a legacy system you might sit down with your user(s) and watch how they interact with it first. What works well? What are their pain points? What could you improve? Basically don't dive in completely oblivious. If the system didn't exist before things become even harder, and I don't have any advice there other than working with subject matter experts where possible.
Whether this is out of scope for your book I don't know. But the key take away here is that you can't presume to know better than your own users.
I would also include a chapter on accessibility. I've been unfortunate enough to have worked with UI people who genuinely didn't give a crap about it. And they'd even get defensive about stuff around colour blindness, attempting to justify their bad choices through poorly made assumptions about the end user (see paragraph one). That's just one small part. I could rant and rave for hours about screen readers, the size of text and fonts.