I am currently teaching a course at Penn on Human Computer Interaction which stress an applied appraoch and only briefly mentions the academic underpinnings of the field. A classic book that provides an insight into basic principles in HCI is Card, Moran and Newell's The Psychology of Human Computer Interaction. It is a bit dated and may be difficult to get but it is well worth the effort to find it at amazon, a used book site (I use alibris) or from a library.
One of the classic topcs in the book is a model of keystrokes that assesses the efficiency of a user interface. You can get a Windows only calculator for this model here, just select KLM calculator. The SYNTAGM site also has other useful resources for HCI including card sorting and mailing lists, well worth exploring!
As the year progresses I will provide other resources for HCI and will mirror them on my website. Later!