It depends on your budget. wozcreative.com is super but if everyone is mentioning Fiverr etc. then that's not within your price range. https://www.ypson.com is another good one. Please think about, if you pay someone $5 for about an hour of work that's not even minimum wage... Also, it's your business image. Don't go cheap...
If you'd like to find a great graphic designer, you could contact Full Sail University here: https://fullsail-csm.symplicity.com/surveys/referral
I'm currently a student there studying graphic design, and they're always looking for recent graduates contract, part-time, or full-time work. Hope it works out!
You can check out freelancer.com and post your project and your specified budget. The good thing about this is that you can check out portfolios of the interested freelancers and pick the one that best suits your preference.
The best place I know is Behance, on that page people post their portfolio and you can see all the works they have made. It's really cool and easy to use it.
Nothing talks better about a designer that its work.