My assignment involves calculating the molar heat of solution. How do I solve the molar heat of solution? 

Molar heat of solution is the amount of heat absorbed or released when one mole of the substance is dissolved.
How to calculate it ..it depends on the information given in the question ...however most of the time it is calculated using a calorimeter.Let us say there is a substance X and you have dissolved  10 g of the substance in 100 mL of the water and the resulting solution has density 1g/mL .On dissolving a rise in temperature is observed delta t = 10 Deg C .Let us say molar mass of x is 100 g
then use equation
q= m .c .delta t   = 100*4.18 * 10 = 4180 J
so number moles of x = 10/100 = 0.01 mole
It means 0.01 mole of X gives 4180 J
so heat releases is 4180 J /0.01 mole = 418000 J = 418kJ
so molar heat of solution is 418kJ

It can also be calculated by using lattice enthalpy and enthalpy of the hydration

Enthalpy of solution
= Lattice enthalpy (endothermic) + Enthalpy of hydration ( exothermic)