Can highly recommend Camping Ca'Savio,
Have been there many times, its a large site, great for young families, and older couples,,,no good for those looking for a lot of night life,,,close to Venice and Lido de Jesolo
We went for years when the kids were young and went ourselves last year and are going again this year.
They have their own website http://www.casavio.it

We are just back from the Cote d'azur and are also thinking of Italy next year. Went to Lake Garda in 2003 and it was fantastic so we were thinking of going the extra 70 miles and booking for Venice. The drive is not too difficult (provided you have a stopover) and you can keep the kids amused by having them guess which country you are going through next (we went through 5 in total). Also, depending on where you are in the UK, it might be worth taking a North Sea Crossing and cutting down on the UK driving. We went Hull- Zeebrugge this year and you get a good early start with the 0830 arrival on the continent.

If you want to try staying at Garda, Camping Eden is good site in San Felice del Benaco but, as with most Lakeside sights, it is very hilly. Pool could also be better.

Please keep posting if you hear of any good sites -