Yes, good idea. When it comes to sailing breaks with the family, I have often looked for somewhere that combines nice accommodation with easy launching, trailer storage, parking and then good access to the boat.
I'm happy to create a page for this on the website so everyone pls share their suggestions here and I will collate them.
I'll kick off with a recommendation:
Mylor Yacht Harbour: One of my favourites; Mylor is a small harbour just north of Falmouth with some on-site holiday cottages. It doesn't get easier than this because you can keep the boat on a pontoon 100m from your cottage. There is also plenty of trailer and car parking. I love sailing on the Fal and Mylor is perfectly positioned for this.
http://www.mylorharbourside.com/ and
http://www.mylor.com/.
Here are a few others I know of but haven't tried:
St Anthony-in-Meneage, on the Helford river. Holiday cottages plus launching, storage and moorings.
http://www.stanthony.co.uk/Redcliffe Farm camp site, Wareham. Camp site on the Frome at the NW end of Poole harbour. Has it's own slipway and plenty of trailer parking. About a 10 min motor down the Frome to Poole harbour, but is much quieter than most Poole slipways and is part of the camp site. I've never camped there (mainly because I live 15 mins away!) but use the slipway a lot. Also a good spot for canoeing on the Frome.
http://www.redcliffefarmcamping.co.uk/Rockley Park, Poole. Don't know much about this other than it is a caravan park in Poole which has it's own slipway, boat park and sailing school.
http://www.rockleypark.co.uk/