Estar is used to describe location, health, or any condition that is only temporary. There are a few tricks to remembering this one. If you make it a habit to think that "estar" meant "to be feeling or located" or it will cover about 90% of the times you will use it!
Cyber Profe
Guided Notes
Profe Loco
Sr. Jordan
AIB (at 8 minutes)
Golpe a Golpe
Lightspeed Spanish
Learn Spanish Through Music
Sra. J