If you want to do the really creative stuff you’ll need to buy a copy of Visio but PowerPoint, Word and Excel are more than capable for the majority of flow charts.
Go to your Insert tab in the ribbon and select SmartArt from the Illustrations menu. You will be presented with the following menu:
There are tonnes of graphics to play around with. Select a category and a template from the list and fire away. Here is an example of a simple company hierarchy which is very quick and easy to knock together.
You can customise the shapes colours, formats, sizes, etc and right click to add a new one before, after or next to them.