do you have an electric pump with it?
If so it will inflate in about 5 mins (I have practised mine and thats how long it took... me all by myself
BLOW UP THE FLOOR FIRST!
then the bottom and second chamber, then the third but only a tiny bit...
put on the liner
then inflate the 3rd chamber all the way.
Unless the hose hasnt been used before you will need to sterilise it first.
I think half an hour in a sterilising solution is fine but read the bottle / tablet box and follow instructions. (perhaps sterilise in the bath, and make sure the solutions is in the whole of the hose)
Best to put a plastic sheet on the floor. (the birth pool in the box one is non slip) but i guess anything will do, especially if you use towels etc on top on the floor as well
Yes a thermometer for checking the temp
and when you come to fill it, make sure you have your boiler set to hot.
also have you got a tap adapter for the hose?
Good Luck 
I have got a waterproof single mattress terry sheet that i plan to place on my sofa, so if i am wet or bleed etc there is no way it will reach the cream sofa cushions.
I got the sheets from a charity shop for 50p so am happy to bin afterwards if they get gross.