Most qualified retirement plans offer significant tax benefits for those willing to follow a few IRS specified rules. The government wants to make these plans (401(k)s, Keoghs, SEPs and traditional IRAs) available for specific needs, and has established tax law to help eliminate potential abuses of these tax advantaged investment alternatives.
In order to plan realistically for the future you need to have a clear understanding of what money you need when you retire. This will include the cost of living and special activities you will have. It is estimated that you will need to replace 60% to 80% of your pre-retirement earnings in order to keep the standard of living you have had thus far.