Your dog needs a beginning and an end to every command. The beginning is his name, as in "Fido, Sit" This is another reason why I suggest that you use his name to stimulate his interest. Your dog needs to know when each exercise or trick is completed and the Release command will do that.
You can introduce this as you teach your dog the "Sit" Command.
1) With your dog in a Sit, after you have rewarded him for sitting tell him, Release! in a conversational tone of voice (rather than using the higher pitched tone of voice used for praise)
2) Back away from your dog and lift your hands in the air. He should follow you; when he does, praise him, "Good Boy!"
3)If he's hesitant to move, use his leash to gently pull him from position to show him he's allowed to move. When he takes a step, praise him.
4) After the release, let him move around and relax a few seconds before asking him to do anything else
After he knows the Release and is moving on his own, use it at the end of every obedience command. Using his name at the beginning and the Release at the end gives the dog clear guidance and parameters.