Here's something I've done on Potty for Piggies, hope it helps!
Q: What IS Secret Santa?
A: Secret Santa is Potty for Piggies and The Guinea Pig Forum working together to give back to rescues, who give so much. It started on TGPF a few years ago, but I took it on last year and linked it with P4P to make it bigger and better. We are fully supportive of the rescue culture and want to thank those who do what most of us cannot - give every day of their lives to those in need.
Q: Which countries' rescues are involved?
A: We currently have rescues in the UK, USA and Australia involved, with a look at working with Canada too.
Q: But I'm in (insert non-listed country here) - can I get involved?
A: YES! We have Santas all around the world; you can order a number of small furry items through the countries' Amazon page without the hefty charge of posting abroad.
Q: I don't have a lot of money to spare, can I still join in?
A: YES! Most Santas send 1 box of goodies, and this doesn't have to be expensive - you can fill a shoebox with nice treats for around £10/$16USD/$18AUD/€13EUR plus the postage - you don't have to break the bank.
Q: Can I send more than one present if I want to?
A: Of course! You can pledge to send more than one gift if you like. Every Santa will be assigned one set of piggies to start with, and then after everyone gets to send one gift, we'll see who still needs a Santa and give those out too! There is a chance you might offer more than one gift, but only get one set of piggies - this just means there's a lot of generous people out there who want to give too.
Q: There's a rescue near me, can't I just go and donate some items to them?
A: Whilst we encourage giving to rescues where possible, Secret Santa is all about sending a lovely parcel through the post, as a nice surprise for the rescue to know that we really appreciate all they do. We want to spread the loooooooove

You can, of course, still give to your local!
Q: Can I ask to be allocated a specific rescue?
A: We try to match people with a different rescue to one they have perhaps adopted from, to spread the love and kindness all around the world, with rescues that you wouldn't normally give to. However, if there is a genuine request then all effort will be made to try and make it possible.
Q: Oh my goodness, this sounds amazing! How do I get involved?!
A: Simple! Send a PM to PottyForPiggies and say just that! Tell me you want to join in! Tell us where in the world you are and how many presents you want to send
Q: I've pledged a present, what happens now?
A: You'll have had a response saying you are on the list - if you haven't given the needed information (location and number of gifts) then you will NOT be on the list, please make sure you tell us! The rescues will start giving names around mid-late October (to better inform who might be in the rescue at Christmas), with a little information such as age and special needs (such as medical needs) Then you'll be matched with some special piggies and you can start preparing your gift!
Q: What kind of things can/should I put in my gift?
A: The best gifts are a mixture of treats for the guineas and supplies for the rescues - if, just for a week, the rescue doesn't have to buy the supplies, then it will help. You can include toys, treats, cleaning materials (like bin bags, rubber/disposable gloves, disinfectant, bottle brushes) medical supplies (such as syringes, syringe food, OTC medicines, shampoos, cotton buds/Q-tips), food bowls and water bottles, fleecy items, vegetable seeds, vouchers for pet stores/supermarkets to buy food and veggies, and, if you want, a little Christmas card! You'll be informed if there's any special needs that will affect your gift - giving hard treats to a piggie with bad teeth is a bad idea! Otherwise, treat them as your own! You could also include a little treat for the rescue owner if you want to!
Q: What about when I've posted my gift? How do I know it gets there without giving away who I am?
A: We ask the rescues to keep us informed when presents arrive, so it can ease your mind. We also ask them to send us some adorable pictures of the piggies with their presents, so we can see what a lovely impact everyone's gifts are making!
Q: I haven't heard about my gift and it's been ages since I posted it/I haven't seen my piggies' photos!
A: Please have patience. Secret Santa has been planned with just 1 pair of hands, and there's lots of co-ordination involved with a lot of people. The last thing needed is for people to start complaining - this is all done out of generosity in the rescues and co-ordinator's spare time. Last year there were people getting a bit cross and upset was caused. We don't want that again this year! The rescues are also a lot busier at Christmas, so it will no doubt take some time before your photos/information arrives.