Well, there are a lot of ways to answer the questions you have. First let me say this (although I may get flamed for saying this). A lot of the vitamins and minerals you get from veggies can be gotten from a good multi-vitamin. BUT, it is always better to get your nutrition from raw food vs supplements. Also, if you actually eat more veggies, it will help control your appetite.
But, onto answering the more direct question. You really can't go wrong with greens. I'm not much into veggies either, but what I do is I often put cheese on them and make them as one of my "protein/fat" meals
Granted, you can't do this all the time, but it definitely helps change things up a bit. When it comes to diet, the two hardest parts are: 1. Getting bored of the food and 2. Keeping portions right
As far as working out on the eliptical machine, it's good that you are up to 30 minutes now. Though, even with "cardio" it's not always about the amount of time you do it. A big part of it is "what all can you do in that time". Stick with a 30 minute workout for a while...but instead of doing it all at one pace or at the same resistance level, vary the pace/resistance, and you will notice a big difference in the workout. Also, always keep a notebook of what you've done. It helps track progress.
On a side note: Chances are, because of your size (which I don't mean to offend), you should see weight loss happen pretty quickly when you start to do things right. This can be a HUGE motivator...so just go with it and keep it up. If you find something that works especially well, keep at it for a while.