Would this be pronounced like "woo" in english, or does the -ew ending have a different pronunciation in klingon?
I'd describe it thusly:
we is pronounced as in "wet"
The final w makes the same sound as the first one.
Perhaps it helps to imagine Elmer Fudd asking "Wew is that wascaw ow a wabbit?".
The sound is a little different, but it's not a sound we normally hear in English, so it's hard to describe. Perhaps you could think of it being like weh-oo.