Does your employer offer a matching contribution pension plan? If so, give yourself a raise! It is a guaranteed return. Consider even contributing beyond the amount your employer will match but ALWAYS contribute to maximize the match. The IRS has rules and yearly contribution limits. Check them out at http://www.irs.gov/Retirement-Plans/401(k)-Plans.
Very carefully review your investing options inside the plan and select the appropriate mix of investments to make it grow! With generous donations and good management your account should keep growing. It will eventually become a large part of your financial support when you retire.
If your company has a retirement plan what is the matching contribution rate? Please comment.