This now leads to inputting this information into the software that you are using to manage your project.  How important is it to understand the software application that you are using to manage your projects?  Not understanding what the software does or how it works can result in giving false information and dates to Sponsors, Stakeholders, and Team Members.  Most software applications have many advanced settings that people do not even know exist.  It is extremely important to figure out how you want to track information in the schedule and set it up correctly before beginning the project.  If you are going to be tracking duration then make sure that the settings are set on fixed duration, or if you are going to be tracking effort worked of the resource then make sure that the settings are set on fixed work, etc.  Trouble will definitely start to arise if these settings are not being used appropriately since this is how the dates are calculated in the software.  This now leads to a lot of other very important questions: 1) Are the calendars in your project set up correctly with all of the holidays and time off?  2) What type of constraints will be used in the plan?  3) Do you understand how these constraints are affecting your project and critical path?  4) How will you be defining critical activities and using critical paths in the plan?  5) Are you using a baseline to be able to show variance and slippage on tasks in the plan?  6) Do you have multiple views set up to fit the needs of the different audiences that will be viewing the plan?  7)  How often will you be updating status on the plan?  How often will you be changing the Data Date in the plan?

As a Project Manager you are managing time, cost, and scope/quality.  Managing any of these without an accurate schedule is very difficult and probably inaccurate.