Are you flipping or buying & holding? That may seems irrelevant - a roof costs the same no matter what. But your finishings (flooring, light fixtures, kitchen appliances) vary depending on your target market. White appliances in rental are fine, but if you're looking for top dollar in a flip, you may need to spring for stainless-steel.
Grab a notebook and go to a Home Depot or Lowes. Act as if you were getting estimates for your dream investment property. How much is carpeting installed? What are the differences in water heaters? You'll be getting ballpark estimates, but this is helpful when talking to contractors - you'll know if they are vastly overpriced.
Have you listened to any podcasts? While it's great to get an agent and start looking, you need some more people on your team. Start vetting contractors now, get some names of real estate lawyers, ask people if they know a good plumber. You want these contacts as soon as possible.
Good luck and let us know about your first deal.