Sorcerers are arcane spellcasters who manipulate magic energy with imagination and talent rather than studious discipline. They have no books, no mentors, no theories—just raw power that they direct at will. Sorcerers know fewer spells than wizards and acquire them more slowly, but they can cast individual spells more often and have no need to prepare their incantations ahead of time. Also, unlike wizards, sorcerers cannot specialize in a school of magic. Since sorcerers gain their powers without undergoing the years of rigorous study that wizards endure, they have more time to learn fighting skills and are proficient with simple weapons.
Sorcerers use a system called "Essence," allowing them to burn Constitution points to gain Essence, which can be expended to regain spent spell slots. For more details, see the Spellcraft System.
Sorcerers will automatically use the higher of Charisma or Intelligence for their spellcraft skill bonuses.
You can start with one of the default basic familiars, but during play, you can "Bind" other familiars. The level at which you can bind a creature is limited to your caster level. For example, if you are a 1st-level Sorcerer, you will not be able to bind a 3rd-level familiar. See the Familiar System for more information.
Sorcerers gain access to Improved Familiar automatically at level 1.