I spent a lot of time doing a birth olan with my first which was mainly focused on what we would do at home, rather than a hospital plan. It heavily feautured my OH and worked really well, this is what we did and will be doing this time :) This is also set out in rough order of what I needed as labour progressed from early to ready to go to hospital:
Have him help organise some activities that you've planned together to do in advance, like ensuring your favourite films are available or running you a nice bath.
Have him prepare you some food you fancy in early labour - very important to eat even if it's just fruit or a smoothie.
He can be in charge of making sure you are drinking and weeing at regular intervals - ideally both once an hour at least.
He can also be in charge of downloading a contraction timer app on his phone and doing timing them for you.
I didn't actually want a bath in the end but had a nice shower and DH helped me get groomed and ready for labour, as it was hard to do with a big bump! He can also run you a nice bath if it will help.
Have him give you a massage on your back or shoulders, or help with breathing exercises.
Make it his job to be in contact with the midwibest, if you feel this will disturb you.
Later on as pain gets more intense it is helpful to use him as a birthing prop - to lean on etc. He can also rUn your back or hold a hot water bottle where you would like it if it helps.
One of the biggest things he can do is be a force of calm and constistency when you are going through such a range of things physical and emotional. If he is moaning or anything, that will put you out and stress you. Good luck!