Birthday party newbie - what's the protocol these days?

[Meandacat]

DD has just been invited to her first (non-family) birthday party. The party is for another girl at nursery, at her home, for a couple of hours in the afternoon. I have no idea what is the "done thing" for parties these days!

1. What does DD wear? Party dress or normal togs?
2. Should I give a gift?
3. If so, how much should I spend, and what do I get? Obviously, I have no idea what toys this child may already have.
4. Should I take anything else, like contribute to food or even just biscuits for us mums to have with a cuppa? (And am I correct to assume that I am expected to be there too, to watch over my little one. She's only 28 mos).

Enlightenment, please!

Party clothes for an at home party. Yes to a present. Books are a good plan. My friend always gives pajamas. You could give stuff that gets used up if you are worried about duplications. Like bubbles or play doh. Or a sticker book.

You don't need to take anything and you probably would be expected to stay.

Don't get special clothes though!

Agree with savoycabbage.
If they have a 'party dress' then that's nice to get the chance to wear it before it gets outgrown, but if they don't every day clothes are fine. Yes to taking a present, but no to taking something for the adult hosts. Only need to spend a fiver on the present, and, as SC says, something that gets used up / lost or something you can add to is always a good bet - things like balls for the garden that get lost / kicked over the fence or those fuzzymitts that catch the ball or a little bdminton type set, etc. as well as books. Thing with books, if they've already got it, it's easy for them to regift

In my experience:

1. whatever your DD wants to wear. I've seen the full range from jeans and tshirt to full on disney princess dress and tiara.
2. yes
3. IME people tend to spend around £5 - £10. Good stuff to get is age appropriate art and craft stuff, books, a cheap lego dulpo set, jigsaw, hair bobbles or clips etc.
4. no

Thank you!

Am relieved at the £5-£10 estimate on this gift. I'd personally thought no more than a tenner, but then you hear such horror stories of competitive gift-buying and party bags. Books are a good idea... I am am librarian, after all.
But I'm liking the lego/PJs/fuzzymitts ideas as well.