I haven't fished Rutland Water but I have done a fair bit of boat fishing on Llyn Brenig and my local water Llyn Cefni. From your question I take it that you haven't fished from a boat before ? but presumably have some bank fishing experience.
To start I would say look serously at the following; Lifejackets, how to work the engine and something comfy to sit on. I presume at Rutland if you ask nicely they will provide some sort of lifejacket and show you how to work the engine.
Other essentials would be a drouge and to keep your tackle, sandwiches etc in something waterproof.
If you can, choose a boat partner who fishes with the opposite hand to you (left if you are right) although this is a partnership made in heaven. If you both fish with the same hand then one of you either has to cast off his other shoulder or be very careful casting over the boat. Some sort of routine for who casts when is useful as is a good hat/hood and EYE PROTECTION.
In terms of actual fishing then the hard part is to find the depth and speed that the fish are taking at(ask at the lodge about patterns etc). With two fishing as a team it makes sense for one to fish a floater the other an intermediate/sinker to try and gauge what the fish want. For the floater you can try dry flys or normal pulling wets. For the sinker one of the most effective techniques is to cast out long then retrieve the flies until you have about 15 to 20 feet of line left and then let the flies hang (count slowly to 10)before casting out again. I hope this is of help to you and tight lines.