The Norfolk Broads
The M1 of the waterways! Hiring a boat is easy, lots of places to SAIL a day boat. Just remember YOU have right of way but don't be silly about it - if a motor thinghy is heading towards you in a hesitant and unsure manner indicate which way you want them to go - usually behind you!
I can pariculary recommend Hickling Broad and a run out to Potter Higham as a nice days journey. If you want some decent wind head out to Thurne (rather expensive launching fees) but no trees!
And Oh!....make sure you have a licence for the day/week/season. Don't stick it on your boat if you are down for a short visit - you can't get the bloody thing off! Apparently, best keep it handy in the boat and wave it aggressively to the nice Police/Ranger operative.
Below are images of Blakeney and Wells - I have not sailed a small boat out off here - nether should you, unless you know how you are going to get back!