how to know if the house is worth mailing to

[Victor Glushak]

hello i have been scouting my neighborhoods that i would like to start investing in

and have been writing down any addresses of homes that look like they might be possible deals 

my question is 

how exactly do i know if the home could be a possible deal or if someone just forgot to cut the grass that week?

is there any little bits of info that people look for in the county records that help clarify if the house is worth mailing to?