The following article is an excellent resource that presents retirement planning in a checklist format, and discusses areas you should check and evaluate prior to retiring.
Your Retirement Planning Checklist [Market Watch / The Wall Street Journal]
AARP also has a Retirement Calculator that can provide you with a personalized snapshot of what your financial future might look like depending on how much you have put away in retirement savings. This is a great tool that assesses all aspects of retirement and can even provide you with some goals to help you achieve the lifestyle you desire as a retiree.