I am looking to work from home doing Customer Service, Troubleshooting problems etc. but am not sure what the scam sites are.

They are all scam sites...

Unless you are hired by a brick and mortar business that "lets" you work from home... (highly unlikely for a new hire) its going to be a scam.

There are not "sites" there re companies that hire you direct, some may allow work at home, most require you to be at a call center