I'm about to take the plunge and try rooting. I'm very new to this meaning I don't even know what "flash" means. Based on context, I think it means something like install. Before I actually try and do this I need to find ROM. Is there a good list out there that has the names and some of the main features, including pros and cons of each?
Flash does basically mean install.
About the feature comparison of ROMs, the closest I have seen was
this thread (link to a google doc in the OP). It isn't really up to date, and only hits 7 of the probably 50 or so ROMs that exist. Being that there are so many ROMs, some of which update rather frequently, it would be hard to update and maintain something like that with any sort of accuracy.
Figuring out features isn't too hard though. Most ROM threads will have a list of some of it's main features in the main post, or perhaps one of the following. Many are pretty good at making changelogs too, where you can see what changed from build 1 to build 2....etc, so you can actually get a more full list that way. Of course this means you will have to do some snooping through various threads (perhaps multiple forums, as some devs only post on one forum to make their life easier), no one stop shop. But still it isn't too hard to get a general idea.
Pros and cons, are basically impossible to say. Performance decides on so many factors, many ROMs should be on pretty even ground here. This includes actual speed of running the device and battery life. Some folks have better experiences with one ROM over another, for whatever reason. But there are folks that have great experiences, and perhaps bad experiences, with many ROMs and kernels. "OMG this ROM/kernel combo made my device so fast. It is also getting great battery life, I don't think I will ever have to charge my device again." Then the next post is "My device stutters and I am getting terrible battery life. HELP!!".
There is also the fact that people like different things. There are folks that love the bleeding edge, give them every feature you can pack into the ROM. Then there are folks that are perhaps overwhelmed by those options, or perhaps only use 2 of them, find the rest useless, and feel the ROM is a bit bloated for their needs.