@Angela Schroeder Hey Angela! Welcome to BP!
Rehab numbers are tricky for a newbie. Books and podcasts are a great way to get a general idea, but I've found that they still won't make you feel 100% confident because renovation costs vary based on the market you are in. Hearing what somebody pays in New York isn't going to help you a ton. If I were you, I would be doing a few things:
1. Look at your competition to see the types of finishes they're using. Carpet or hardwood for the floor? Granite or formica countertops? Vinyl or clapboard siding? Once you know what's being used, you could now look up the prices (hardwood floor on Home Depot, for example) to get a rough idea of material costs. You then can call contractors in the area to get a rough quote (ask a flooring contractor how much he would charge to install X sqft of hardwood, for example). You'll now have an idea of labor costs for flooring, in this example.
2. Talk to investors in the area. They're doing it already! There's nobody better to learn from.
3. To piggy back of number 2, partner with those other investors. Find and bring them a deal and you'll be able to learn so much through one project.
Hope this helps! Best of luck.