One thing to consider is whether you have housing where a barking dog will be acceptable. Poms are very vocal. Very vocal! If you live in a free-standing house and plan to keep the dog indoors except for supervised outdoor potty outings, that works fine. As long as you don't mind the barking. They do bark!
You will also need to keep that pretty coat combed out. Combing daily is probably all it will need, if you do a thorough job. It is very thick, so it will take a few minutes a day, even for such a small dog, and even after you and the dog work out your combing routine!
Poms need to be fed frequently to keep blood sugar stable. Three times a day will likely work for an adult dog. Unstable blood sugar can cause hypoglycemic seizures.
With any dog this small, you need to get to the veterinarian promptly at vomiting, diarrhea, not drinking--dogs that small can get dehydrated VERY rapidly.
I love little dogs! You're making me want another! I had a Miniature American Eskimo, related to the Pom but larger at 15 1/2 pounds. She was incredible. I had an obedience instructor who had and trained Poms. Great little dogs.
-----
Kathy Diamond Davis, author, "Therapy Dogs: Training Your Dog to Reach Others," 2nd edition, and the free Canine Behavior Series articles at http://www.veterinarypartner.com/Content.plx?P=SRC&S=1&SourceID=47