That's a pretty broad question, since there are vegetables which grow in different seasons, and each takes it's own specific time. To further complicate things, different varieties take different amounts of time between planting and harvesting.
You can ask us if you have something specific in mind. An excellent place for precise answers are actually seed catalogs.
Books can tell you basically on say, pumpkins, but there are a lot of varieties out there. Some are relatively fast, whereas others take all season.
Good seed catalogs, such as Territorial, Bountiful Gardens, and others, will not only show you what's available for you to grow, exactly, but tell you how long each will take to bear.
Mind you, they cannot control extreme weather conditions, or poor soil, but it's close.
For fruits which are in the form of trees, bushes and vines, ask a local nursery, or look at online catalogs for places like, Raintree Nursery. Of course, if you are wondering about a specific variety, someone here may know the answer to your question.
For approximations of days to maturity of veggies, if you don't have seed packets, try googling <veggie name> "days to harvest" (for instance, for chard you would type in chard "days to harvest" ).
Remember however that this will vary GREATLY depending on your location, soil type, etcetera. Experience is the best guide, so for the first few years you may be largely in the 'obtaining experience' part of the curve Also you have to plant things at the right time of year in the first place, otherwise your harvest may take much longer or never occur.
For fruits, as a gross but reasonably useful generalization, strawberries will bear the first year; cane fruits (raspberries etc) the second; bush fruits (currants, blueberries etc) the second or third unless you bought really tiny plants or are abusing them; common types of tree fruits will not (and should not be encouraged to) bear til after 2-3+ years; and nut trees may be decades. You should look up a book about the particular types you're interested in though.
get the book "How to grow more vegetables' than you ever thought possible on less land than you can imagine" by John Jeavons. This book has good charts for vegetables fruit fiber crops compost crops along with garden layout plans for 1 person to 4 persons. Highly recomended.
John's book is great, though I'm not sure it will help with this, unless one was going to try to grow using the method discussed. Still, a worthwhile read, I think!
Thank you so much for the information. I have no specific veg. or fruits. Just wanted to know more and to see what I might get myself into. I love to plant veg. and harvest them. I am just a little impatient. I just want to get an idea.