How do you re-establish grape vines?

We recently moved into a house that has been used as a business for the past 20-25 years. We are in the process of turning it back to a home. The property backs onto a small tributary of a local river (read - almost non-existant at this point, but lots of swampy/ woodsy vegetaition.) Last fall we cut back a lot of vines and what we thought were weeds, and laid down mulch to make flower beds. This spring, we've noticed that some of the vines are gowing leaves that look like grape leaves (and we've even noted what looks like tiny grape clusters). Our neighbors mentioned that the family who used to live in the house before it was a business were avid gardeners and did in fact grow grapes. So I'm guessing that what I'm seeing are edible grapes, but they've been cut down to the quick. No trellises, and the vines look like roots that are coming right from the ground. How do I re-establish them? Do I need to trellis them yet? Should I prune off the grape bunches to encourage the vine to grow?

How do you re-establish grape vines?
remove the mulch and cover the exposed roots with a little soil! they'll poke back through in a matter of days! put something up to train them young!
Reply:The other answers were correct. This was what the vines needed, a vigorous cut back. A yes they will need support.
Reply:no let them grow to a three foot height then place a fence for them to grow on