I was asked at my last Microsoft Project training session whether tasks can be linked on the Gantt Chart itself rather than in the Entry table.
Although it is not my preferred way of working, it can be done.
Type tasks and durations in your Entry table first. Then on the Gantt Chart, select the successor task and drag it to where you feel it should start in relation to the predecessor task. You will then get a dialog box as shown:
You can create the link by selecting Link them. Then click OK.
If you drag a bar further it will allow you to keep the link but instead of adding lag time between the tasks it will instead create a Start No Earlier than constraint.
So it can be done, but I don’t find it the easiest way!