Activating Celerity for one round requires the expenditure of a blood point.
You may take Two actions in a round instead of one.
You may take Three actions in a round instead of two.
You may take Four actions in a round instead of three.
You may take Five actions in a round instead of four.
You may take Six actions in a round instead of five.
The use of your additional actions happens *after* your first claimed action. So, if you are in a fight and 3 people are acting, you take your first out of X actions in the given turn while everybody else takes their action. Then, your additional actions happen.
These actions must be physical actions. Normally, without Celerity, you must apply a dice pool penalty to act multiple times in one turn. Using celerity, one performs these actions without penalty, including full movement, gaining a full dice pool for each separate action. Extra actions gained through Celerity may not be split into multiple actions.