Hello Justin,
"zhen" 's pronunciation is kinda like "jean" in English. But the "ea" from"jean" is E, right? Take the pronunciation of "en" from "end" to instead of E sound. So, the sound of "zhen" is: jen.
"de" is a slight ponunciation. You see, "to" from "today" is a slight sound, right? So do "de". Just change "t" to "d".
If you have any further questions, I'd be more than happy to help you.
Dandan