For the past year I have been consuming an unhealthy amount of coffee and read a lot of papers starting with some very broad reviews (which are great at directing you to specific individual papers), coupled with some basic experiments. My project has been fluidic, changing with successful and unsuccessful experiments.
As the year progressed I gradually read more and more specific papers, although I still read quite a few loosely related papers because some ideas are transferable. Although my project started with no specific question, which did unsettle me at first, I have come to enjoy the freedom it has allowed me to develop the project into one I enjoy and can develop (with my supervisor's help of course :-)