You may want to be more specific in what you are looking for in a fleet. Pretty much all fleets say they are casual fleets, which may or may not be the case. Perhaps talk about what size the fleet you prefer or what kind of people you would like to be around for starters, or what you do want/do not want in a fleet.
We like to talk to people before sending an invite. We are a multi gaming fleet since 2002 and know the game. We like to have fun and do events and just enjoy star trek. We have members from UK, USa, and Canada. We use Xfire and Teamspeak to keep up in game and out of game with members. Our members come from all different backgrounds and most have family's and jobs. If you want to join us add me in game @mjaybird or go to http://www.unitedfed.net