For Sprint Planning, you'll need the following:

What you'll need: The Product Backlog, post-it notes, and black sharpie pens.
Setup: A large table that the whole Scrum team can fit comfortably around.
Time-box: A maximum of 8 hours for a 1-month Sprint; for shorter Sprints, the event is usually shorter. For a 2-week Sprint, a maximum of 4 hours should be sufficient.

There are two questions essential to Sprint Planning. The first is, "what are we able to achieve in this Sprint?" and the second is, "how will we achieve it?".