Similar to Pikey's answer, OpenRAVE (http://openrave.org/) lets you input the kinematics of your arm in an XML format (different than URDF), and will give you the Jacobian, FK, IK, motion planning, etc for your arm.

If you want to do it the traditional way, many standard robotics textbooks outline how to go from DH parameters to the geometrical Jacobian. I like this book: "Robotics: Modelling, Planning and Control" by Bruno Siciliano, Lorenzo Sciavicco, Luigi Villani, Giuseppe Oriolo (https://www.google.com/shopping/product/18328483085519729280). For all but the simplest of arms, you will want to use a symbolic algebra package to help with this...

Similar to Pikey's answer, OpenRAVE lets you input the kinematics of your arm in an XML format (different than URDF), and will give you the Jacobian, FK, IK, motion planning, etc for your arm.

If you want to do it the traditional way, many standard robotics textbooks outline how to go from DH parameters to the geometrical Jacobian. I like this book: "Robotics: Modelling, Planning and Control" by Bruno Siciliano, Lorenzo Sciavicco, Luigi Villani, Giuseppe Oriolo. For all but the simplest of arms, you will want to use a symbolic algebra package to help with this...