Following your arrest, you will be taken before a magistrate (judge), either in person or via teleconference. That person will explain to you what you are charged with and set your bond.  You will most likely not see a magistrate until the day after your arrest, and if you are arrested on a weekend, it will probably be the following Monday.  You will not be able to bond out of jail until you see the magistrate and he or she sets your bond.