if you hit "jump as a group", they will wait to jump.  then all of your ships go at once.

Fleets suffer fewer casualties in general, provide a quick button to select a number of ships, give them a formation (tho this is quickly abandoned), and allow for advanced tactics like setting how far apart you allow the ships within to move.

There are certain fleet behaviors u shoudl be aware of.  One thing, telling a ship to retreat that happens to be in charge of the fleet, will cause whole fleet to retreat.  This is a pain.  I generally tend to fleet ships of the same type.

Right click on the move button.