If you would like to swim in the springs, I know they have a little pool section opened on weekends, but it's not really enough to swim in but let me tell you about some of the other springs in the area. First of all, there is Wekiva Springs. this one has a large spring with a big swimming area, and 12 miles of hiking trails. I know there are signs for this one off of I-4. I'm not sure about the ones I'm going to tell you about now.
There is Rock Springs. Here, you can swim in part of the river. (where at Wekiva, you can swim at the source) In the winter, due to the warm water, you can see manatees swimming here in the wild. It's pretty cool.
Here's one of my favorites. Kelly Springs. Outside of the park you rent inner tubes, and then ride them down a two mile river. Also, if you have snorkeling equipment, you can just float down the river, going through rocks, watching the wildlife, etc. This is like a natural lazy river!
Finally, there is Delieon springs (I probably spelled it wrong). Here you can rent boats, swim, and eat in their resturant. With this resturant, you enter an old sugar mill, and you have tables with a grill in the middle. (Picture a smaller version of a Japanese Steakhouse table). You get pankake batter, and then you cook your own pankakes. Thery charge per picture of batter, and they last a while, so it's a big meal for cheap!
There are many other springs in the area, but these are my favorties. I'm sure there's someone you can write away so you can get get directions to all of them.
Hope this helped a little more!