One big challenge is finding healthy meals that you actually enjoy. For several months, eating was very difficult, because I was just putting healthy foods together and eating them. Once I worked out some recipies so that eating was actually enjoyable, things went fine. For instance I started adding a small apple to my salad. What a flavor boost.
If you have a farmer's market, you should try to buy from there as much as possible. We have a year-around market, and my diet shifts a bit through the seasons, as different fruits & veggies come in season.