Hi Agnih,
In your PM, you asked about wallpaper removal and painting. So here goes.
I am also a relatively new investor so I would take my tips with a grain of salt. I honestly did not know much about the contractors here in Philly when I fixed up the first property. The good thing for me was that most of the repairs required were cosmetic. That being said, I signed up for Angie's List to get a list of reputable contractors. I find the problem with Angie's list is not reliability, but cost. It seems like the contractors are so well known now, they are so busy and can price their work at exorbitant prices. That being said you can see what people have spent on a particular piece of work. This allowed me to get an average estimate for how much each piece of rehab was going to cost.
Cutting to the chase, I used an AL coupon for $200 of wallpaper removal for 6 hours from [I'll tell you in a PM]. They required I believe 10 hours or so, the price came out to ~$370 to remove about ~1000 SF of wallpaper. They charge by the hour so depending on how easy/difficult it is it could be $200 for one room or three rooms... Glue can be a tricky . Anyways if you plan on doing it yourself I'm not an expert, but it seems like a lot of elbow grease.
Painting, I did by myself. After the wallpaper was stripped I just went to Behr and picked up the Ultra Premium with the self-priming formula. I actually only coated with one coat of paint thru the 1200 SF house. Although I will say most investors say two coats. I left the ceiling alone since it was actually in pretty good condition (Ceiling white color). This took roughly 3 separate days. Obviously there were way more repairs to be done, but many of them I hired out the work. I tried to refinish my hardwood floors myself but that turned out to be a disaster. I used a Oreck Multi-floor orbiter to refinish the floor, but that only left circle scratch marks on the floor. Rookie mistake. I would suggest hiring a professional hardwood floor refinisher or you could take a swing at it by renting a drum sander or U-sander from Home Depot.
As for roofing it really depends. I would just go online and have three separate contractors give you three separate quotes on the work. Again you could turn to AL and see the average pricing.
Good Luck!