We did one for dd1 8th birthday. There was an info pack with party game suggestions from the company although she wanted a pyjama party with a dvd. We did have a kind of teddy bear picnic nothing to do with not having enough chairs for 11 children with pombears and a teddy cake and some mini teddy biscuits.
You need to make sure that you have a label or different colour ribbons to put on them to label them to save arguments over who stuffed which animal, they do care. Also they sent loads of stuffing. We only used 8/10 packets and they still looked obese. Keep some back for another project. Do the stuffing on a mat as it does go everywhere and it is handy to just roll up the mat and deal with the mess later so you can get on with the party. Do also check all of their arms and legs to make sure they are fully stuffed. I had put a little more in the head before the party so they didn't need to.
Do make sure that you check the seams before the party. Ds's one had one which was not fully stitched but I didn't notice until after stuffing it. The customer service was excellent, they gave me a choice of me stuffing it or a prestuffed one. I opted for the latter as ds(3) was quite attached to it, so they just sent a prestuffed replacement and an envelope to return the first one so I could quickly swop it.
It was a fun and easy party and they all enjoyed it.
Thanks so much for your detailed reply 3birthday, that's all SO helpful. I'll be taking your suggestions on board, think we're ordering kittens and puppies and just the 8" size. Sounds like your party was a definate success! Thanks again you're a X