Tara, there are loads of lists about and some great threads on here too. The back page of a Mothercare catalogue was where I started as they have a good list (as do BabiesRus and other shops I think). Check out the product reviews section on here for advice too http://www.fertilityfriends.co.uk/forum/index.php?board=406.0
Muslin squares! Lots of them, they are soooo handy for dribbles of the chin and leaky nappy situations (quickly sit baby on one to save your skirt / trousers!!)
I found a bean bag mega helpful - new babies are obviously too small for bouncy chairs (unless they have v good head supports) so if William didn't want to be left but I need to shower or something I'd pop him on the bean bag near me and he'd be quite content. I think it was because it sort of molded to his shape so he though he was still getting a cuddle (I'd say not to use like this when they can really wriggle in case they sink too far in to it though) It was also nice to lean against in bed when breast feeding.
A little top and tail bowl for nappy changes.
Cotton wool balls or washable wipes (I prefer these - look on ebay )
Night lights to keep it subdued when doing 3am feeds (or low wattage bulbs)
Scratch mitts or better still baby grows with 'built in' gloves.
Following on from Sades suggestion of Fenugreek, try Fennel tea - quite yummy and said to help maintain your supply.
Breast pads for those leaky days!
A big bar of chocolate to reward yourself for being so clever!