Know that many chemical reactions balance best by trial and error. Here you find a few helpful guidelines, but you still need to be flexible.
Review nomenclature rules for naming ionic and molecular compounds. See Resources below for a helpful website. (See "How To Name Ionic Compounds" and "How To Name Molecular Compounds," under Related eHows.)
Write a simple skeletal equation of the formula from the words given. Use your nomenclature skills as reviewed above, here.
Balance atoms in the most complex molecules first, and the simplest forms (such as single elements) last. This often will make the balancing process shorter.
Make the number of atoms on the left match the number of atoms on the right by adjusting the coefficient in front of each compound or free element. Leave the subscripts as they are in the original skeletal equation, because you are not creating new atoms.
Clear any fractions in coefficients by multiplying by the denominator of the fraction.
Check your final equation by counting the number of each type of atom on each side of the equation to be sure they are equal.