It kind of depends on what veggies you like, the area you live in, and the "time".
For example, tomatoes. In my area, fall tomatoes are generally a waste of time. Its just too hot to get them started in the ground in time to mature before first frost. What I do is plant some of my spring tomatoes in a spot that gets late afternoon shade...and I have tomatoes through the spring, summer, and fall as a result....but have never been successful at planting and harvesting fall tomatoes.
Peppers are much the same way, i.e. plants you start in spring will continue to produce through the fall months...but it can be difficult to start them in fall and get a harvest.
In general, the plants that do best in my area when started in fall are the cool season crops....Brussels, brock, cabbage, kale, collards, kohlrabi, carrots, beets, radishes, spinach, lettuce, onions, etc. Most all of those will produce all the way through fall and winter (if we have a mild winter)