Invites
I used smilebox for invites for DD's bday that I jsut sent out. They were great as I didnt have the money to order invitations. You can put a photo of DD on the invite in cute designs and music plays to it and then you send it by email.
Food
We are doing a sausage sizzle and then just plates of nibble foods like cob dips, plattars, fruit and then I will do some fun things for the kids.
Venue
We are doing it at home
Cake
Getting it made as I am hopeless and baking cakes.

HTH