At the end of each iteration in an Agile project, the team typically holds a planning session to prepare for the next iteration. During this session, the team should plan the backlog by estimating and reprioritizing the user stories as new information becomes available. This ensures that the most valuable and feasible stories are tackled next, aligning with the iterative nature of Agile methodologies. The other options, such as developing a user story analysis, running a spike, or discussing risks, may also be relevant activities in an Agile project but are not the primary focus of an iteration planning session.