It really depends on what you're feeding. If you're using a very high quality food with plenty of vitamins and minerals (which the good ones will have) and rotating protien sources (such as with each bag in the brand, getting a different flavor), it's not necessary unless there's something specific you need to address with your dog. Check the vitamin and mineral contents on the ingredient list of the food you're using and if your vet is proficiant in nutrition (most aren't unfortunatly) go over it with him/her. I also look for a food that has an extensive list of ingredients beyond the protien such as fruits, vegetables and minerals.
If you do decide to use one, get one that is a "whole food suppliment". I'll post a link at the bottom for one that the vet I worked for who was very much into nutrition sold and recommended (mainly only for dogs or cats that had to be on a prescription diet temporarily, for his own dogs because he did home made raw and anyone who had an extra need)

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The only suppliments I use are for my Beagle - she's hypothyroid and on an rx for it and 12 years old, so I give her their whole food suppliment for senior dogs (it has glucosamine and omega 3). I also use their regular adult one for my Akita in the winter months since her skin gets dry under all that fur so she needs the extra omega 3 fish oil and it works wonderfully.
www.missinglinkproducts.com/
Missing Link is great, but there are plenty of other good ones on the market. It can be overwhelming though lol so figured I recommend one for you

This one I know is available at Petco.
congrats on your new furbaby, it's so hard to wait isn't it?