Many young and middle aged adults are making the smart decision to plan for their future, and this involves developing a plan for retirement in their later years. It is common for working adults to participate in their work-sponsored retirement account, making at least the minimum contribution necessary to take advantage of an employer matching program. Beyond this step, however, many are lost with regards to how to develop a feasible plan for retirement.How Much Do You Need?One of the most important first questions to answer is how much money do you need to retire. This is a question that often stymies many adults. Retirement is a period of your life that can span for decades, so you do need a significant nest egg built up to live off of for such a long period of time. Running out of money during this period of time is something that you simply do not want to contend with. The amount of money needed for retirement will vary based on your lifestyle, what your retirement plans entail and if you will still need to pay for expenses like housing and a car payment during that period of your life. You also should consider the amount of Social Security income that you are expecting to receive coupled with other sources of income, such as a guaranteed pension. The difference between the income you know you will have and the expenses that you will have is the amount of money you will need access to on a monthly basis during retirement.How to InvestFor most people, simply stashing away cash into a low interest savings account will not help them to grow their money in a manner that will support their desired lifestyle in their retirement years. It is necessary to invest in stocks, mutual funds, CDs, real estate and other types of investments to grow your money in a faster way. You should take time to research the options available, then start regularly saving money to purchase these investments. Over time, your nest egg should grow more quickly with these different types of investments.