Just adding my thanks to those above for all the hints and tips. We've just spent two days at Legoland, taking advantage of an Inset day for the boys (age 10 and 6). We booked a two day/one night stopover at the Holiday Inn in Maidenhead, so we could make the most of our time there.
On Sunday, it was pretty busy with some fairly lengthy queues building up on popular rides. We'd bought Qbots (basic ones) for the day, which were fantastic - I would book the next ride as soon as we'd been checked in on the current one, so our queuing times were minimal. The longest queue was for the Dragon's Apprentice, so we timed that one for just after lunch, and used the hour's wait to picnic and play on the slides nearby. All in all, we managed to get on 14 of the 20 Qbot rides in one day (and could probably have managed more if we'd tried harder!).
We ended the day with the water rides, getting progressively wetter. The boys loved the pirate log flume, and the Viking river rides best, but particularly enjoyed firing the water cannons at other riders
. Near the end of the day, we were able to come off the ride and head straight back into the queue line with only a couple of minutes' wait. We had a change of clothes available for the boys, which was pretty vital as they were cold and dripping by the end.
The hotel was about 20 minutes' drive, although we took a longer route to avoid the traffic. The restaurant food was nice enough, and perfect for DS6 who is very difficult to feed. Our family room consisted of two fold away beds in a large double room - a bit squashed, but fine for a night.
Today (Monday) was much quieter and we were able to get directly on the Laser Raiders ride which our boys enjoyed. In fact, we came out and as there was no queue, ducked through the barrier and went on for a second ride. We went on the Boating School, which had the longest queue of our visit, at 30 minutes (no Qbot today). We took the boys to the Duplo Drench Towers - the boys loved this, but the water was freezing so they only lasted 10 minutes or so before they got too cold and gave up. We got some food (BBQ opposite Driving School - £5.45 for a sausage or steak baguette - nice enough), and then finished off with a few things we'd missed (Star Wars miniland - DS10 loved this!) and a revisit to the Viking river ride for a final soaking! We left the park mid afternoon, so as to avoid rush hour traffic.
Just to reiterate some of the points others have made above, we found the refillable drinks bottles were excellent (we reused it on day 2 - not sure that's strictly allowed though!). The pirate show was very good - DS10 got very involved in that one! Car Park C is the place to be - we made our way there both days. Qbots are excellent on busy days - even the basic one makes a huge difference. Having two days meant we could relax and enjoy the time - no great pressure to do it all on the first day.
All in all, we had a great time 