It is essential to understand what your stakeholders need and expect from your project. This process is called "Collecting Requirements", and you will want to collect all of them.. Start with your Stakeholder Register where you record "Needs" and "Expectations". Also look at your Project Charter which contains the Statement of Work. Additionally here are some tools to help you Collect Requirements.
Two definitions will be helpful to clarify the process:
Expectation: A one-way desire or perspective that a Stakeholder has about HOW the project will be managed. Expectations must first be discovered then documented so they can be managed. (One Stakeholder's expectation might be that every one of his/her needs will be included in the project!) We manage Stakeholder Expectations by either delivering what is expected or by working with the Stakeholder to help them understand why their expectation cannot be met, so they can adjust their thinking to be in line with what can be delivered.
Need: Requested, deliverable outcome of the project. Needs lean toward the WHAT, and WHERE of project deliverables. Needs can be prioritized into 'Must have', 'Should have', and Nice to have.' Needs must first be discovered then documented so they can be managed. We manage Stakeholder Needs by either delivering what is requested or by working with the Stakeholder to help them understand why their need cannot be met, so they can adjust their thinking to be in line with what can be delivered.
These examples are worth repeating. In a project to build a new Emergency ward for a hospital, one Stakeholder had the Expectation that emergency services would not be interrupted. His Need was that the new ward would have 50 chairs in the Waiting Room. As an Information Technology example, a Stakeholder has the need for on-line monitoring and the expectation that all ordered materials will arrive on time.