A brain computer interface is an artificial intelligence system that provides the brain with a way to communicate with the outside environment. This paper aims to provide guidelines for biomedical researchers by discussing each phase of the construction of a Brain Computer Interface. It explains invasive and noninvasive BCI. Then, it presents the most commons methods employed for designing a BCI and discusses the artifacts removal. Finally, this paper summarizes the advantages and disadvantages of the presented methods and discusses the future steps into this field of research.