Introducing a new dog into the family?

ok just today i took on the responsibility of having a nother dog. I have had a weenie dog that is 13 months old for over a year now, but today i brought home another 12 month old weenie dog, humane society needed a good home for it. problem is my original dog is very territorial about chews, toys, water bowl etc. even when i try to give the new dog a different to my original dog goes after the new one for it... what do i do, they have been trying to get in fight all day... how do i get them to become friends? ohhh the new dog is not yet spade... is that one of the reasons?