Ok, first stop is the Watercooling sticky over in the Overclocking section,
http://www.tomshardware.co.uk/forum/277130-11-read-first-watercooling-sticky
this will get you some ground knowledge on loops and there is a section on closedloop coolers like the H100 as well that you should read in there
the 'many' parts you'll need can be broken down simply,
a Pump to pump the water round the loop
a block (One for each chip you wish to cool, Cpu,Gpu's etc)
tubing to go between the parts
two fittings for each component, one in, one out
radiator/radiators (the radspace needed depends on what you are cooling)
and most usually a reservoir,
go over the sticky and you should start feeling a little easier about it all, and theres a few regulars here that will happily steer you in the right direction,
but we won't just post a shopping list, that doesn't help you much in the long run, its better that we help you learn
Kits are available to make things slightly easier for you but ask before spending ok, some brands are good, Xspc, Swiftech, some aren't, Thermalright,Zalman.
please ask us before spending money on something that we'll groan at

Moto