I usually just left-click on the symbols on the right. Shift-Click will let you select, say, Bombers and Fighters together. Then Ctrl-# to stick 'em on a group.
You can also Alt-RtClick the listing in the bottom right to remove specific marks if you're looking to, say, grab all your ships and then weed out all the MK Is for an assault against a planet with four Ion I cannons. That may be a bit further than what you're asking though.
Click-Drag also works for grabbing a mass of ships as they come out of a wormhole or something. Something else you might want to turn on is auto group-move in the ctrls menu. I find it saves me a lot of grief when moving my primary fleetball around. It's rare I want the bombers out in front without anti-fighter frigate support, for example.
