It's a little dated (is it sad that 2006 is "dated"?), but I still find "Designing Interfaces" by Jenifer Tidwell (it's an O'Reilly book) helpful once in a while for basic UI/interaction thoughts.
Agreed on this: it's handy because it has a catalog of design elements and tells you when you should and shouldn't use them. That's pretty helpful compared to more abstract theories about UI stuff, for some people.
