After completing your research strategy/plan (Review facts, Determine Legal Issue(s), Determine Process including timeline, budget, and end product)
You are almost ready to begin searching for sources!
First determine if your facts and legal issue are likely to be found in Federal, State or Local law: Jurisdiction.
Federal law generally includes: Bankruptcy, Civil Rights, Copyright, Immigration etc.
State law generally includes: Most crimes, Estates and Family law, Landlord tenant, Motor vehicles, Personal injuries, etc.
Local law generally includes: Animal control, building regulations, parking, traffic, zoning, etc.
Then determine if you can use free official sources or if you need to subscribe to a low cost database to get helpful annotations.
When using free sources make sure you verify their currency and authority (I recommend governmental, educational and library sources). While you might find something that looks good using Google, unless you can verify the accuracy of the information provided you should not rely on it.