ˈknʊbːɪɡ
* kn: Pronounced like "kn" in "knock," but with a slightly softer "k" sound.
* u: Pronounced like the "oo" in "moon," but shorter.
* bb: The double "b" indicates a longer "b" sound.
* i: Pronounced like the "i" in "machine."
* g: Pronounced like the "g" in "go."
The stress is on the first syllable (knub). The overall sound is quite soft. It's difficult to perfectly capture in writing, but hopefully this gives you a good approximation. Listening to a native speaker pronounce it would be the best way to perfect your pronunciation. You can find audio pronunciations on online dictionaries like Forvo.