OK, first of all, good viz and warm don't go together when you're talking about springs. Make a note of that. 72F is much colder than it sounds. Good news is there are no thermoclines because the water is moving... As far as good sites, you found one of them.
The State of Florida has a website for all of its parks
Welcome to Florida State Parks but I don't know if there is a single site that includes all the diveable springs. This link might be helpful too as it lists private springs too.
Florida Springs: Scuba Diving and Snorkeling in Florida Springs (Please note that not all of them listed here are diveable.) I also reference "Diving Guide to Underwater Florida" on occasion, but don't get too excited with it.
As to what you're going to see, that depends on the spring. I frequent a few of them and each one is markedly different. You get the general sandy bottom but the aquatic life can be very diverse. At Blue Spring I have found remnants of ocean life in the form of sand dollars and I have been told there are shark teeth there, but have yet to find any. Blue is your basic hole-in-the-ground spring that has a cave to penetrate if you are certified. Alexander Springs is a wide and shallow basin bottoming out at around 27'. Take a hotdog with you to feed the fish if you go there. Troy Springs is also a hole-in-the-ground but in the run you can see the bottom ribs and nails of a Civil War era steamboat that was scuttled. Ichetucknee Springs is a blast for tubing, especially when it's crowded in the summertime. You can snorkel down the run, but not dive it. Not anymore anyways.
Ginnie is a popular private spring for divers as well as Blue Grotto and Devil's Den... except I would classify the last two as sinks, not springs. All three of these charge too much, IMHO. But that's just me... It was worth diving them once.
Not sure what's good in the panhandle/big bend areas... I like to keep my treks limited to a day trip and some of those sites would be a little too far for driving back and forth in one day.
Make sure you bring your buddy and c-card.
Ken