Vacant city residential lots

[Rusty Scott]

I've been casually looking at some city residential lots on the market..mainly to just hold for the time being, and possibly build SFHs on in the future. 

These are standard city lots where the original homes were torn down....and a fair amount of new builds are happening in the area, slowly. And old homes that are salvageable are being rehabbed.

I have zero experience with this..but would like to learn. What should I be aware of and be looking for while researching? 

Not trying to do anything complicated like rezoning or anything.