Reading material doesn't cause harm. Your thoughts and beliefs about it, however, may do so.
If you are coming from a Christian paradigm, you probably should not jump into occult traditions that Christians have been indoctrinated against. If symbols and images used are too different from what you are comfortable with, you won't be able to accept them, and your doubt and fear will prevent you from developing.
You can begin your studies, however, with occult teaching that is rooted in Christian symbology. For an absolute beginner, I would recommend 'Discover the Power Within You' by Eric Butterworth. It gives an occult interpretation of Jesus teaching, in a way that is very approachable for beginners especially from Christian backgrounds.
If this line of thinking interests you, you may be interested in metaphysical christian writers. Eric Butterworth said in 'Discover the Power Within You' that Christ opened a window into consciousness, and tried to encourage others to look through the window. Instead, we adorned the window with gold and gems, and it became a cross. People still come to the window, but they worship the window and no longer seek to look through the panes; this is traditional Christianity. Metaphysical or New Thought Christianity seeks to look through the window again.