I live in the Northeast, and though I'm aware of what seasonal vegetables and fruits are available in some cases because they are growing in my garden, or in containers on my deck (pictured...the plants are MUCH bigger now!) other delightful local fruits and vegetables are yet to ripen and be at their peak.
Blueberries are ripe for the picking now and into August. I have already picked early tomatoes, cucumbers and basil...early as opposed to last year when the season started much earlier due to a very warm Winter and Spring. Farmers Markets in the area are open for business, and it is a wonderful time to be enjoying foods harvested locally.
If you would like to find a complete guide of what is in season in your area, about.com has done a nice job of putting guides together by region for us to use and enjoy. They call them "Regional Produce Seasonality Guides".