When you are about to initiate a new project, you should capture the basics of project information. If you don't, you're walking into a minefield. Even before you write up a charter, you should be able to answer the following: Problem (or Opportunity) Statement - Describe the business reason(s) for initiating the project, specifically stating the key business problem or opportunity
Project Description - Describe the approach the project will use to address the business problem
Project Goals and Objectives - Describe the business goals and objectives of the project. Refine the goals and objectives stated in the Business Case (which you should also have)
Project Scope (Requirements) - Describe the project scope. The scope defines project limits and identifies the products and/or services delivered by the project. The scope establishes the boundaries of the project and should describe products and/or services that are outside of the project scope.
Critical Success Factors - Describe the factors or characteristics that are deemed critical to the success of a project, such that, in their absence the project will fail.
Assumptions - Describe any project assumptions related to business, technology, resources, scope, expectations, or schedules.
Constraints - Describe any project constraints being imposed in areas such as schedule, budget, resources, products to be reused, technology to be employed, products to be acquired, and interfaces to other products. List the project constraints based on the current knowledge today.
If you can articulate these seven areas, you've proven you have at least a basic understanding of what you're up against. If you can not, you better go back and find the answers. It is a lot cheaper to answer a question when the project is still initiating, compared to deep in executing.