1) Just do it -- just sit zazen. Many questions, confusions, and apparent contradictions are resolved simply by this act alone.
2) Zazen has allowed me to lighten up in my social and professional lives. As a PhD student in preparation for an academic position, you are bombarded with things you have to do but much of your schedule is left for you to decide on a daily basis (much of your schedule isn't set in stone). As a result, I have historically experienced profound anxiety and worry related to motivation and when to work on things. After practicing zazen fairly regularly, I have found I can be more productive with less time, and with hardly any of the anxiety. Most importantly, I have found that, sometimes, it is OK to do nothing...it helps when it is time to "do something."
3) Lastly, zazen increasingly makes every daily activity a meditation.