from my experience trying to find them on the internet before there used is pretty hard...... but if you make a thread explaining what kind of coupon code your looking in the right section on the forum I'm sure someone will be nice enough to help you out that's what I did and I hope this helps cheers!
If I am looking for some sort of coupon code I Google it and it usually comes up if not then most likely there is any available.
Google it and find what you need. Usually, you can get those discount coupon codes from some blogs which often share coupons day by day.
Suggest use google alert, then you can get the coupon code from the website that update frequently and the latest coupon code
retailmenot.com is good, got me a great discount off MediaTemple's (gs) And some good NameCheap discounts too
The best way and most accurate is searching in Google with your exact niche along with "coupon code or discount code" then you will see huge lists of results for you to check and test