Clear signs of B, B+ class neighborhood when looking online

[Rob Ko]

Aloha guys, I am looking for my first investment properties on general sites like Zillow, Realtor... 

Usually I am looking in areas I do not live in as my home market is too expensive. I am looking to buy in B, B+ class neighborhood. 

I would like ask more experienced investors for the tips how they recognize these areas and also what is their process of choosing a market. Appreciate your feedback.