Most ROMs can be found on XDA Developers website. Most ROMs have screenshots and/or YouTube videos so you can check out the features prior to installing, however I have found that installing the ROM on your device and exploring it for yourself is the best way to tell if you are going to like the ROM or not. Just make sure you do a Nandroid backup( Backup option in your custom recovery...ie ClockWorkMod or TWRP) , and if you don't like the ROM, then you simply restore back to where you were before you installed it (without losing data/contacts etc).
If you follow the install instructions to the letter, and use the proper ROM, you shouldn't have any issues. Just make sure you read over what you're going to do a few times over, maybe watch a ROM flash video on YouTube, to familiarize yourself on what you should expect while doing it.