Even without having studied "human computer interaction design" you don't have to reinvent the wheel as a programmer to realize a user friendly, functional and consistent user interface: Take a look into one of the various UI Libraries as listed below. I bet it can save you a lot of time especially when implementing and structuring your UI functions.
A really great presentation and collection of recommendations, ideas and inspiration for every web project.
Patterns from different point of views and especially use-case driven examples.
...and for your interest, even more (well, I prefer not to focus on too many sources, so I won't list them up here in detail):