I planted several varieties of squash, beans, onions, cabbage, lettuce, etc. in the spring. I am very much a beginner. I can't tell whether what is coming up is a weed or not. I also don't know when something is ready to be harvested. Recommend a book or a website?
Weed From a Vegetable in the Beginning
I assume you have rows of vegetables. You probably planted the seeds approximately the same distance apart? Repeated appearance of a plant that does not resemble the weeds that come up gives you confidence that they are the vegetable. In harvesting, you want your vegetable to look like those you see in a grocery store. Plants that produce their crop underground sometimes just have to have a sample pulled to check size. You will gain experience and start to recognize plants.