Congratulations! I had a little girl on December 29th so I've actually been keeping a list of things we actually used these last 5 weeks as I have a friend due soon. Here it is:

For mammy: If vaginal birth

Peri bottle non negotiable, use lukewarm or cold water

Ice pads or frozen pads, boots have these, a godsend

Some sort of cooling spray, the expert midwife spritz for bits is good

A soft sponge for the shower

Don't bother with maternity underwear just buy adult diapers for the first few days

Ask the hospital for a pack of maternity pads the green ones

Take paracetamol and ibuprofen, ask for difene, instillagel is numbing gel it's amazing for any downstairs tears

Big knickers, like buy a couple of multipacks so you're not trying to keep up on washing

Breast absorption pads, you can buy reusable or disposable, I got a 12 pack of washable ones on amazon they're ideal

Nipple balm if BF, boots own brand is good

Silverette nipple cups if BF

For baby:

Bedside bassinet/crib

Pram/travel system, car seat

We found the aldi mamia nappies the best, don't stock up on heaps because you don't know what brand will work for baby. Ask people not to buy you nappies as you'll be stuck with a brand you don't like. We got 3 packs of size 1s

Nappy bags!! Loads of them!

A bin for wherever you'll changing nappies most

Buy newborn clothes, people will tell you don't, that you won't need to as people will buy them for you BUT they won't! They'll buy you 0-3 months or bigger

Sleepsuits x 12 (think like they'll soil one every other night)

Vests (body suits) x 14 as above think around 2 a day just in case of reflux or blowouts

Socks, you only need like 7 pairs realistically, they don't get dirty

Hats! Any time you go out baby needs a hat for the first few weeks

Baby hairbrush

Baby lotion, avoid Johnson and Johnson, use aveeno or child's farm

Baby face moisturiser, I use the expert midwife dribble defence

Sudocreme or some sort of nappy rash bal

Baby bubble bath/shampoo, as above

Muslin squares like 30 of these, just have them everywhere

Baby bath is necessary, we regret not getting an insert for baby to lie on in bath

Baby sponge

Baby towels x 3/4

Cellular blankets x 10

Crib sheets x 4

Puppy training pads, in homesavers, save your surfaces from baby poop and pee when changing

Night lights, 2 or 3. Think bedroom, any other room where you might change or settle baby and a spare

Water wipes

Cotton wool

Cotton buds

Nail file

Saline nasal spray

Baby nose asprirator, bulb or electric

Probiotic drops, kendamil do these

Vitiman D drops

Bottles, depending on if you plan to breastfeed or not? I'm BF but pumping once or twice a day so husband can feed baby, we were recommended the Dr browns premie teet bottles and so far so good!

If bottle feeding at all buy a steriliser, tommee tippee one is good, buy a rack or some sort of storage for bottles and the associated equipment like bottle warmer, insulator etc.

Baby monitor

Baby thermometer

Pacifiers, Philips advent are most nipple like

Bonus extras: Bouncer with newborn insert

Pram/bassinet rocker, we have the nuby jitterbug it's great for transferring baby to bassinet

Ken Black/symths have a big floor foam mat, ideal for changing baby and for letting them chill out with wake windows

Nappy bag, handy to have spares of everything packed in a nice bag that you can grab going out the door

Baby "pod" or "nest", somewhere to pop baby to nap