It doesn't matter which industry you're in or project you're involved with, these 5 points should be taken every time to properly plan your project:
1: Set the Direction
Before you start out, set the direction for the project. Do this by clearly identifying the project vision, goals and deliverables. State the overall timeframes for delivery and clarify the amount of resource available. Determine what is "in scope" and "out of scope". Identify the benefits and costs in delivering the project and any milestones and constraints. Only once this is agreed with your Project Sponsor will you know what it is that you have to achieve.
2: Task Selection
You're now ready to start planning. Identify the groups of tasks that need to be completed to build your project deliverables. Then for each group of tasks, breakdown those tasks into sub-tasks to create what is known as a "Work Breakdown Structure" (WBS). Your WBS is essentially a hierarchical list of tasks, in order. Assign start and end dates to each task, as well as task durations. Always add a little extra time (e.g. 10%) to your durations, providing you with contingency. Next add Milestones to your plan. These are tasks that represent major achievements along the way.
The next step is to add links (or dependencies) between project tasks. While there are a variety of link types, most Project Managers add "finish-to-start" links so that one task cannot start until another one finishes. To make your project achievable, only add links between tasks if there is a critical dependency between them. Remember, when one task slips, all tasks linked to it may slip as well. So use links wisely.
4: Resource Assignment
Now comes the fun part, assigning resources. A "resource" may be a person, equipment, location or materials. Against each task in your plan, assign one or more resources required to complete it. As you assign resources, watch your resource utilization. In other words, make sure you don't over-assign a specific resource to multiple tasks, so that it's impossible for that resource to complete everything assigned to it. So to make this easy for you, plan the resource utilization as you assign resources to projects.
5: Baseline, Actuals and Reporting
With a fully completed project plan, you're now ready to save it as a "baseline", so that you can later compare your progress against it. Then start recording your actual progress against the plan. Every day, record the amount of time you've spent against each task. Also record the new planned start and finish dates, and monitor the overall project completion date. Report on progress as you go. By regularly updating the project plan with your progress, you can control the delivery of your project and meet those critical goals set.