I suspect it depends on what charity you're dealing with. I adopted an animal at a wolf sanctuary once and got a photo, certificate, and so forth.

If I were going to sponsor an animal now I'd look for one at the Performing Animal Welfare Socieety website. Pat Derby does good work.

I got our dog from a rescue group - it's the best thing in the world!
The website to go to is www.petfinder.com
It's a listing of all animals up for adoption in your area. You can browse by breed, size - anything. All the animals come with photos, description and will have their shots an get spayed/neutered before getting adopted.
These places will NEVER give you a pet you haven't personally met. The way it works is:
You find an animal online, get in touch with the rescue group and set up an appointment to meet it. Many groups also have adoption days where you can show up without prior appointment.
They will carefully check your background to make sure that you can provide a good home for the animal - some groups even require somebody to check your house to make sure you have a fence or yard (differs with each organization - mine only required I fill out a form).
There is an adoption fee - for dogs usually between $100-$250. This covers the shots, spaying/neutering and basic costs the group encounters.
The animals usually also get microchipped before you adopt them.
Adopting an animal is one of the most rewarding things you can do.... and you usually wind up with a happy, grateful and loving companion.
I know plenty of people who have gotten puppies from breeders - complete with pedigrees and everything... and most of them have either character problems or health problems.
The advantage of adopting is: you know what you're getting.
I'd recommend adoption to anybody who isn't planning on breeding or showing their animals.
We adopted our White Shepherd Moxxie at five months old.
She was a rescue from Georgia.
When we got her, she was skinny, dirty and frightened.
We met her at one of the adoption days and could see right through that first look to what a terrific dog was underneath the dirt.
She's now a happy, loving, amazing dog.
Best thing that's ever happened to us!

unfortunately im one of those people that wont put cash in the mail or over the internet to a charity im not completely familiar with. i found local rescue groups that take old towels, leashes, collars, bowls etc. thats where i do my material donations.

I sponser a donkey at the Donkey Sanctuary and they send me loads of details. It's £15 per annum per animal and really it is just like making a donation, but it's all good fun.