There are several good sites, depending where on the Island you want to be based.
The Orchards, on the outskirts of Newbridge, access off the main road between Yarmouth and Newport. Has most essential facilities, shop, etc and is a well kept friendly site.
Southlands CMC site on the outskirts of Newchurch, access off the main Arreton to Sandown road, usual CMC standard.
Whitefield Forest, access off the main Ryde to Brading road, large pitches set in a forest setting, immaculate main facilities, no shop etc but Tesco just down the road.
Whitecliff Bay, Yaverland, access OK towards Bembridge . Site split into two main parts, on the Right hand side of the road the main cabin/lodge site with main reception etc.
On the Left the touring area with its own reception, however having driven past this site last week there is a lot of work going on and it looks like it is being turned mainly into static van sites with a relatively small touring site at the bottom of the hill.
Then there are the various Parkdean sites at Nodes Point, Bembridge, Lower Hyde at Sandown, Thorness Bay between Newport and Gurnard, all singing dancing sites which are very busy in season.
Check ferry fares carefully, Wighlink are expensive, Red Funnel are usually less, but not by a huge amount, although RF do have a concession rate linked to some sites for specific lengths of stay and are much more affordable.
Getting on and off the ferries, EASY, drive on, drive off follow the deckhands instructions. No need to remove aerials.