New to Chickens- any tips on accessories?

Hi, I'm new on here. I'm going to get my first 4 chickens in a few weeks. Any tips on what I'll need to do/buy to prepare for their arrival? All I have done so far is ordered them a house and a pen. I have seen a few lists of the basics (eg 'a feeder') but I'd appreciate any advice about specific products or ways that I can help them to settle in to their new home. Thanks.

Your coop and run should be large enough for them.  A guide for size is 2 to 3 sq m clear floor space per bird for the run.  Best to have more than one feeder and drinker to allow the lowest in the pecking order chance to get their fair share.  It also helps in case of leaking/spillage of water as they need fresh water available during the day.  Grit and crushed oyster shell should also be available at all times for the birds to help themselves. 

They will need shelter from wind, rain etc. and a shady spot in case the sun comes out. 

I use THESE drinkers and various sizes of THESE feeders.  Mine are in a covered run so no need for a rain hat.  If their feed gets damp it soon goes mouldy which is really bad for your hens.  I store my feed in THESE which double up as feeders.

I also have a couple of old galvanised watering cans full of water which they love drinking out of (don't use apple cider vinegar in these).

That should be plenty for you to start on.   

I store pellets in the bag in a metal dustbin(freecycle) but only buy a 2kg bag of corn. some corn is put into a plastic container, which when shaken the chooks come running over..this makes it easier to put them away at night as well as them occaisionly wandering out of the garden.
I have a covered area, where the house and food/water is as well as an open run covered in bean netting on top. run areas are secured with dug in wire as well as big door, so house can be moved outside. 2 clay flowerpots with tent pegs to secure to ground with oyster/grit. water and food are suspended to make eating/drinking easier.
No foxes around here, but the odd rat turns up, trapped and disposed of.
I get a bale of straw, bale of sawdust. I use folded newspaper for nestbox and straw on top. Takes a long time to compost so either bin or burn.

Another comment on food storage. Don't get a big container for your main store. It rarely gets emptied and so flour moths or similar will make a whole new ecosystem in the bottom.
My experience is that the big round feeders (about £10) are good. With traditional rectangular boxes the birds either stand in them or tip them over (often both).

If you are getting the chickens at the same time form the same place, you don't really need 2 feeders and drinkers for just 4 chickens. As long as the the ones you buy are big enough the chickens will be able to share without squabbling.

The chickens don't need access to food and water over night, they will sleep through.

some corn is put into a plastic container, which when shaken the chooks come running over..this makes it easier to put them away at night as well as them occaisionly wandering out of the garden.

This was probably one of the most useful bits of advice I was given. I have some in an old metal tin and trained my girls to come to it when shaken by always shaking it before giving them a treat. It saves a lot of bother trying to catch a flighty chicken that doesn't want to be caught and as soon as I shake the tin they all emerge from wherever they are in the garden and will follow me into the run.