Just have a chat with the likes of Cory's or Rexel of2fsh, they'll have all the kit for you, they were a great help to me when we did something similar,may possibly depend on which council you are under...Rodney? Hope it helps mate.

Cable used will depend on the load required, and distance from the switch board. Guessing 2.5mm twin&earth but posssibly 4mm twin&earth. (check this out with a local electrician or at an electrical wholesalers) cable needs to be buried @ minimum of 600mm deep , the cable must be mechanically protected in either orange conduit or with a wire shielded cable, with orange electrical tape buried above the conduit. Always use RCD potection in wet areas such as a pool. These cost a bit but are worth the extra expense as they provide added protection against electrical shocks and are very sensitive.

If the shed is feed off the house and the house was wired under the new regs then more than likely the house and or the shed will have RCD protection already ,so you possibly dont need RCD protection on new Circuit .If the shed has its own distribution board run a new 2.5 mm twin and earth TPS cable to where you want the double powerpoint in conduit ,trench only has to be 500mm deep not 600 hasn't been 600mm for a long time .depending whether you want the timer on the pump only or on both the pump and lights there are weatherproof powerpoints with built in timers able to be mounted outside .If you want the timer to control both easier to mount timer in shed as it does'nt have to be weatherproofand is cheaper .You really need to get a sparkie to look at what you want to do and advise you of the cheapest and best options then you can buy what you want from cory's or where ever .I'm based in Whiti unfortunately or I would buzz round and see you ,but there must be Sparkies from this site in your area to come round for 5 mins and let you know what you need to do 

just run it over the roof auw less work involved

Something safe like this then...