Don't buy too much - I think there is a tendency in the last months before birth to channel understandable nerves and excitement into shopping and think you have to get everything before the due date. And baby equipment companies/ magazines etc... prey on this and get people to think they need super fancy buggies, changing tables, changing bags, baby baths, decorated nurseries etc...(you don't need any of this - and if you find you do you can always get it later)
Don't worry about clothes for the right sex. Dresses on babies are pointless and they will have enough time when they get toddlers to wear pink/blue etc...just buy everything in primary colours or stripes.
What you need is:
About a dozen all in one suits (mainly 0-3, not too many in newborn size they grow out of these in a week or two) and the same again of the teashirt/vest versions with the poppers.
A packet of nappies and a changing mat or two (one in your bag, one in the house)
An all in one coat thingie with legs and mittens built in for a winter baby
A couple of little hats
A cardi or two (much better than over the head jumpers)
I wouldn't buy a cot till 3-4 months - you may find you don't use one at all.
One thing worth spending money on is a decent sling/baby carrier - particularly if you are a walker/public transport user rather than a in-and-out of the car person. The cheap/supermarket ones are rubbish.
Mainly though I'd try to get as much as possible second hand - all this stuff only gets used for a limited period of time, so there is a lot of it cycling around.
The trick is to find someone whose youngest is 6 months-a year older than yours and who isn't planning any more children and offer to take everything off their hands (ask around or if you don't know anyone try putting up a card at the Drs surgery/local school/playgroup) - a lot of people are just happy seeing it go to a good home and will give you bin bags full of stuff.
Charity shops are good too.