John, Mark, and Luke are good places to start, and 1 John and Colossians as well. Depending on how well versed (sorry for the pun) your bf is, he may want to start with Mark or John before Luke. I'm not sure if you're asking for help getting him started as a Christian, or if he's just needing help on a certain aspect.Starting with a gospel, especially John, is a good place to start with a basic "Jesus is this".
For Old Testament, the Psalms (18:30 and 103:1-20, for example) can help. Isaiah has a lot to say on it (ex., 20:48), but is also a book of prophecy and after the Law books (Numbers) one of the more difficult read-throughs.
