If you're getting a puppy, you may want to invest $40 and get a UGODOG. Pee pads are disgusting and often leak through or over the edges. Puppies also like to tear them to shreds. With UGODOG, you can put the pee pads inside of the UGODOG or don't use pee pads at all. It's up to you, but it really works better than using just pee pads alone.
Here's their website:
Replace Your Dog Litter Box with an Indoor Dog Potty | UGO PetCare