I currently have 3 other dogs in my house all either neutered or spayed. The first is a male terrier mix who is 9, next a female daschund/min pin mix who is almost 3 and our newest member a female rottwiler/coon hound mix who is around 2. they all get along well aside from the occasional jelous attention thing now and then. I am addopting a new puppy within the next few weeks, she's a 9 week old daschund/lhasa apso mix and she's just so tiny that I am afraid the others may accidentally hurt her. Are there any tips you can give me on how to safely introduce my newest little girl?

Yes, there is a strong possibility that she may be injured by the other dogs.

Best thing you can buy in this situation is a baby gate. Use this to separate off one room of your house like your kitchen.
Put the new puppy in the kitchen until the other dogs get used to her.
By using a baby gate they can sniff each other without any physical contact.

The rest really depends on the personality of your other dogs.
If they are temperamental and likely to get snappy with the new puppy or generally won't be able to handle a puppy's boisterous behavior, a new pup might not be for you.
If any of them play rough then you may have to keep the pup separated until he/she has grown up or look in your local shelters for an adult dog to adopt, there are plenty that need a loving home and is often great in situations like this where older dogs are involved.