Usually, when people ask me such question, I would tell them to start reading from the gospels first; particularly the book of Luke, if the person like to read a systematic account. However, reading the book of Mark would be helpful too as it is written in such a way that it's easy to be read by the gentiles. After finishing the gospels, I would say, go on to read the book of Acts, followed by Romans. Thereafter, I would move the person into the book of Hebrews.