What's the best way to account for repair costs?

[John Burtle]

I'm by no means ready to invest just yet. I am still doing research and saving $. In the mean time I'm trying to learn as much as I can. What is the best way to account for repair costs on a house? If I see a house for $40,000 but it needs new windows, doors, siding, roof, carpet, paint, flooring, etc.....what is the best way to get a rough estimate on repairs?

What's the best way to get a rough estimate on the costs of those items/labor without having to call a construction company to come out and look at every single house you're looking at? Or do you have someone come out every single time? I just want to learn how I can do some rough estimating on my own before calling someone in if that makes sense.