Check out 'Campsite Search' at top of page, click on 'County' and type in 'Isle of Wight' and you'll find 2 pages of sites listed. It not only tells you about the site, you can also read other peoples views on them!!
Although I've not camped there I have been in a static.... Rookley Park.
Lovley quiet site with pub on site.. limited entertainment.. small restaurant. And the bit i actually liked was the fact we were right in the middle of the Island. No distance to anywhere..... tho it does mean you have to drive, or use the bus.
park resorts quite nice loads of country side bit in the sticks but no need to leave the site EVERYTHING you will need is there but the beach on site is crap everything else kk...........