Make sure you give your first dog lots of attention and fuss when the puppy is around, so she knows the puppy means nice thins happening, and not that she is ignored every time the puppy is there.
Also, your first dog will be the senior dog in you pack, at least for the start, and you need to treat her as such. Feed her first, say hello to her first, take her side in any little arguements they might have. Don't take toys away from her and give them to the puppy, even if they were the puppies toys to start off with. If she gets something of the puppies you don't want her to have, then you take it away and it is yours, not the puppies.
Don't worry about any little arguements they might have - your older dog will be showing the puppy her place. She won't hurt her drastically, it's mostly just noise and flashing teeth!!
Have fun, it's great having two dogs!!