BCI papers for starters

To get started is not an easy task, if you are working on fundamental BCI, then your first thought is to scrutinize what is your IV and DV that you wanna examine.   If you are working on applied BCI, definitely you want to first target which signals you primarily want to work on (SSVEP, P300, MI, or hybrid) and what kind of end results you would like to have.    If you are working on affective BCI, definitely you want to determine what emotion or cognition you want to work to classify/predict.   

Most of these answers can be found in papers, and getting the right papers will speed up your research process

Best papers to read as a starter is always the review paper.  Review paper will give you a general idea what the field is doing, and what are the current problems facing the field (which leads you to find your potential topic!).

There are many excellent review papers in BCI including, 

A good reference book will be Brain Computer Interfacing: An Introduction - Rajesh

After getting an overview, you can start drilling more specific  publications.  When you are reading, try to focus on learning research methodologies which include IV, DV, metrics, preprocessing techniques, topography, EEG validity, models, etc. as this will often help you determine your topic.