Most texts contain a very nice summary of the main theorems. Here is a partial list of topics you should review:

• The Gradient: You should understand what the gradient of a function means geometrically and physically. (Can you relate the gradient to the level sets of the function?)
• Line Integrals: You should be able to compute line integrals, determine whether vector fields are conservative, be able to find potential functions, and know the Fundamental Theorem for Line Integrals.
• Surface Integrals: You should know the surface elements for simple surfaces, and how to compute surface elements for other surfaces. You should be able to compute surface integrals, and understand flux.
• The Divergence Theorem: You should know how to apply the Divergence Theorem — and when to use it. (Is your surface closed?!) You should know what the divergence of a vector field means geometrically and physically. (Can you recognize in simple cases whether a vector field has nonzero divergence from a sketch?)
• Stokes' Theorem: You should know how to apply Stokes' Theorem — and when to use it. (Is your curve closed?!) You should know what the curl of a vector field means geometrically and physically. (Can you recognize in simple cases whether a vector field has nonzero curl from a sketch? Can you relate this to whether the vector field is conservative?)
• Green's Theorem: Green's Theorem is just a special case of Stokes' Theorem. You may wish to study the corollaries about area and the two vector versions of the theorem, one about (2-dimensional) flux and the other about work or circulation.
• Change of Variables: You should recognize simple changes of variables to use in particular problems, and should further know how to effect the change of variables once you have chosen (or are given) the variables. Such problems can be solved either using Jacobians or by viewing them as special cases of surface integrals.