@Adeyemi Opeifa I’ve been pretty much relying on the bigger pockets bookstore and recommendations from members and podcast guests.

If you are interested in the book to learn more it's called Lend to Live and you can get it in the BiggerPockets bookstore in whatever format fits your learning/reading style.  

If you use your favorite search engine you'll find some numbers that can help, sometimes used book stores have old estimators guides.

Ask me how I know.To anyone new to rehabs, I recommend the book from J.Scott in the BP Book store. 

. - Materials that I like are any Bigger Pockets Podcasts, books in the bigger pockets bookstore, maybe start with House Hacking by Craig Curelop, The Multifamily Millionaire by Brandon Turner and The Book on Managing Rentals by Heather and Brandon Turner

To read more about self storage, check out "Storing Up Profits" by @Paul Moore in the BP bookstore.

Brandon Taylor has podcasts that are very good and have a look at the BP bookstore as well.

I just received Carlton Sheets No Money Down, and bouth Find It, Fix It, Flip It, at a local bookstore.

The bookstore & all the other learning tools are great also.

The Bigger Pockets book store if full of great books: https://www.biggerpockets.com/store