I for one love the Everglades national park.
Some thoughts:(for a quickie one day trip)
1. On the northern side if you come in on 41, (The Tamiami Trail), you will pass many air boat ride places. I would pass the ones heading to the northern entrance of the park in Everglades NP and also pass the entrance to the park in Everglades City. You won't see the true Glades there(just Florida Bay and some off shore Keys)
2 Continue on 41 until you get to where all the Mikkasukee(sp)Indian air boat ride places are and take one of them on the right hand side
Along the way there you will pass "Half Way campground" which is National Forest campground and I think is free
3. camping outside the park: after those air boat places, continue on 41 until you get to the big Mikkasukee (sp) gambling casino and turn right onto Chrome Ave. This will take you to the southern entrance of the NP. Along the way the RV park we use (but it is off the road), is "Miami Everglades campground" which has all the amenineties that you would want.
4. Camping inside the southern section. The southern section is our favorite, and you get to see the true glades. the first NP campground is "Long Pine Key" It is a beautiful campground, but has no hookups.
You can get water at spigots and there are rest rooms, (just cold water)
At the end of the road at Flamingo there is a large mostly wide open NP camp ground which is where we usually put our base camp and then take off into the wilderness for multi day kayak camping trips on the 99 mile "Wilderness Waterway".
If you do go as far as Flamingo; make sure to look from the boat docks for the pair of humongous salt water crocodiles that hang out there.
I hope you have a wonderful trip and make sure you have plenty of bug spray (deet) or better yet, a "Thermecell"
Jack L