Hi Krystal, there are quite a few different posts here that talk about the best kinds of dog food... i tried my hardest to look for the link, but i really couldn't find it... But this link should help you out a lot.
http://www.yorkietalk.com/forums/showthread.php?t=69354
My yorkie is 12 weeks old and was initially on purina puppy chow, i heard it was really bad for puppies, then i went out and the guy at the pet store said that purina pro plan for small breed puppies was good... but after reading all the posts, i see that it really isn't. Pro Plan also made my dog really hyper... I didn't think it was the food, but i bought a yorkshire terrier book and it says that if the diet consists of a lot of carbs then the puppy will be extra active... and when i looked at the ingredients, boy was it ever filled with lots of carbs... not to mention the additives and preservatives that the pup really doesn't need!!!
I've just changed Missy to eat Chicken Soup for the Pet lovers soul - for puppies, and she's still active, but not totally hyper like she had ADHD!! lol Let me just tell you how hard it was for me to find a dealer that sold this food!! DAYUM!!! haha it took 2 days for me to find someone close by... Chicken soup has the first top 3 ingredient as protein, and uses Vit E as it's preservative... also has lots of fruits and veggies... but we did, and i'm completely happy....
Good luck!!
PS, you can also do a search on the forum for a specific food if you need more info!