The answer depends on how long you have been a follower of Jesus.
Newcomer: buy a pocket edition or download for your smartphone:
Ready to take your Bible a bit more seriously: Then buy a Bible Study Series. We recommend the Navpress series. Open the Bible Studies tab and select Growing in Christ – the thirteen week course.:
and are not currently accessible. Patience.
Getting serious and wanting a deeper full understanding of your Bible: what you buy now should take you behind the English on the page in front of you. First, go to one of the decent websites:
At these sites, you will be amazed at the amount of material you find. Of the two, we recommend starting with Net.Bible before going on to the Bible Hub which is huge, yet surprisingly easy-to-use.
Leadership: you are being asked to lead regularly and are thinking about congregation leadership, planting, possibly overseas with limited web access. Probably the best on the web (much still to be added) is STEP:
<http://www.stepbible.org/>. it is functionally easy.
Once you have mastered STEP you also need to purchase/obtain some software. Tyndale house has a great assistance page, to help you choose. Go here:
once you have the hang of that lot, you will have realised that it is time to start learning the languages: Hebrew and Greek. Here is an online approach:
Enjoy yourself reading, studying and learning about our great God from the Bible.