A bunch of us are playing right now and we decided to start a fleet together. We are on the federation side cos reasons and you can join as a Romulan too as they can choose and ally at level 10 (Romulans are awesome btw).
There are many benefits to being in a fleet in STO like access to the highest gear and ships by contributing to the fleet holdings projects in many different "bases" like the Starbase or the Romulan embassy to gain the currency for very useful items, we would of just joined an established one but that would of meant a whole lot of issues like earning the right to contribute and then fighting over said contributions before it gets filled etc, so it was far more beneficial to just start one and reap the rewards.
Star Trek Online is F2P and your able to gain cash shop currency (Zen) just by playing and refining Dillithium to convert into Zen, I managed to purchase a top tier ship in 3 weeks or so, so its definitely possible to play completely free.
So if you have played before and want to give it another bash, or a massive trekkie like me and couldn't find anyone to play with or even you are completely new and feel like giving it a go for the first time, then feel free to yell at Rav, Chris or me for an invite. Where on TS most nights.
You can download the game on steam or use PWEs shitty steam clone Arc (cos we need more of those on our PCs right) @ http://www.arcgames.com/en/games/star-trek-online
I will be playing for the foreseeable future even if I'm playing something else too , but with the sea of mediocrity lately I needed one that I had fun with to pass the time as nothing in the near future has me exited.... yet.