The system is thus:
1. Bring up the gant chart view
2. Type in all your task descriptions in the task name column, each new task has a new description, duration, etc.
3. Assign durations to each task
4. Assign predecessors to each task. A predecessor is when one task cannot start until a previous task is finished thus Task 2 - 'Roof the house' cannot start until Task 1 - 'Build the house' has been completed hence Task 2 is dependant on it's predecessor, Task 1.
5. As you look at the Gant Chart on the right now, you will see the project slowly taking shape as each task follows it's predecessor acroos/down the page.
6. Once this is done, you can format the Gant Chart (Format menu - Gant Chart Wizard) and follow the wizard to display the Critical Path, usually in red on the gant chart.)
7. You can also look at the project statictics (project menu - project information, statistics button) to tell you how long your project is going to take. The critical path is the shortest possible duration for your project dependent on the predecessors given.
Hope this helps..
Sim