When starting a new job, employees should inquire about the company's 401(k) plan from human resources or knowledgeable managers to determine if they are eligible. Eligibility typically requires being over 21 and employed for 6 months to a year. For those not eligible, alternative options include Roth IRAs, traditional IRAs, pensions, CDs, or bonds. Roth IRAs offer tax-free growth of principal and fewer restrictions on withdrawals than 401(k)s.