Veterans Education Improvement Act of 2008 - Amends the Montgomery GI Bill educational assistance program for veterans to: (1) increase the rates of basic educational assistance and the time limit for entitlement to and use of such assistance; (2) provide a stipend for individuals using such assistance to pursue a program of education at an institution of higher learning; (3) extend the period for the collection of a fee for the use of such assistance; (4) authorize the use of such assistance for business courses and seminars, courses taken to prepare for licensing or certification tests, and the repayment of federal student loans; (5) allow for withdrawal of the election not to enroll in the program; (6) state that such assistance shall not reduce eligibility for other financial aid; (7) extend the increase in benefits for certain individuals pursuing apprenticeships or on-job training; (8) modify the amount for reimbursement of state and local agencies administering veterans' education benefits; (9) provide educational assistance for veterans discharged under a general discharge; (10) increase the reporting fee payable to educational institutions that enroll veterans receiving assistance; (11) provide additional areas of work-study for veterans; (12) require a five-year pilot program for on-campus work-study positions; (13) increase the number of employees in the Education Service of the Department of Veterans Affairs (VA); (14) require an action plan for upgrading VA information technology used in the administration of educational benefits; and (15) modify the advance payment of initial educational assistance or subsistence allowance.