The business requirements document should accurately, and in detail, describe the purpose of the project. It states what is needed to achieve that goal i.e. what is in-scope, what is out-of-scope, any assumptions that have been made, any constraints that have been imposed and expected timescales.
A Gantt Chart is an excellent project management tool for the scheduling, budgeting and reporting of a project. The easiest, but perhaps not the most useful, tool for creating Gantt Charts is MSProject. Each task is listed on the left-hand side of the chart with a timeline shown on the right. Milestones can be easily marked and the schedule and costs can be easily updated where necessary.