From Harry Potter and the Sorcerer's Stone, Harry Potter and the Chamber of Secrets, Harry Potter and the Prisoner of Azkaban, and Harry Potter and the Goblet of Fire by J.K. Rowling. 

Alohomora- Door unlocking spell. 
Aparecium-Spell to make invisible ink visible. 

Disapparate-To disappear at will. 

Dissendium-A spell that opens entrance to secret passage to Hogwarts. 

Ennervate - Spell to revive someone who's unconscious. (vol. 4, p. 33) 

Expelliarmus - Disarming charm. (vol. 2, p. 190) 

Ferula-Spell to conjure a sling for a broken limb. 

Fidelius Charm - Magical concealment of a secret inside a chosen person charm. (vol. 3, p. 205) 

Finite Incantatem - Stopping charm. (vol. 2, p. 192) 

Locomotor Mortis - Leg-locking curse. (vol. 1, p. 222) 

Lumos - A charm to light the end of a wand (so it acts like a flashlight). 

Mobilarbus-Spell to move objects. 

Mobilicorpus-Spell to move someone who can't walk. 

Morsemorde - Spell to conjure the Dark Mark. (vol. 4, p. 128) 

Nox-Spell to extinguish light on a wand. 

Patronus Charm- A positive force which acts as protection from a dementor. It is conjured up by the incantation expecto patronum and brings forth a guardian that acts as a shield between a Wizard and a Dementor. (vol. 3 p. 237) 

Petrificus-Spell to bind arms and legs together. 

Reparo - A spell used to repair something. 

Rictusempra - Tickling charm. (vol. 2, p. 192) 

Riddikulus - Turns Boggarts into humorous looking creatures. (vol. 3, p. 134-5) 

Serpentortia - Blocks unfriendly spells. (vol. 2. p. 194) 

Tarantallegra - Leg jerking, quickstepping charm. (vol. 2, p. 192) 

Wingardium Leviosa - to make things float. (vol. 1, p. 171)