Welcome to MASA Gavin! So glad you found us and joined!
Please have a look at the other "New Member's" threads. Many have been said and asked already. If you don't understand something - please ask.
BIGGEST THING! DON'T BE IN A HURRY! BE PATIENT! ONLY BAD THINGS HAPPEN FAST IN MARINES! (except getting your life-stock home quickly from the LFS, that is ;-) - as Ocean said)....
Look at the basic requirements what you should be looking at:
= tank (decide on size, whether to buy pre-manufactured, pre-built (by hand), build-it-yourself, have LFS custom build for you, or buy second hand)
= sump (look on MASA for designs - the most simple and the BEST one is where you have an inlet/intake compartment, DSB/refugium/algae scrubber compartment, outlet/return compartment)
= lighting (look at T5 fluorescents, Metal Halides)
= plumbing
= testing kits
= power-heads/pumps (for water flow - the faster the better - MOSTLY - not always)
= temp (heaters), pH, alkalinity, salinity (get hydrometer or refractometer to test), etc, etc...
= skimmer
= phosphate reactor
etc etc etc