Dear Taza Guru: There are no guarantees in real estate investing, except that real estate investing has historically been the best hedge against inflation. When analyzing a real estate invesment, there are several indicators that can easily be calculated. Capitalization rate, cash on cash, return of and on investment, before tax cash flow, after tax cash flow, vacancy rate of rentals in the area, and average market rent of other comparable investments. You just need to decide what your goals are for all of the above indicators of investment value and purchase only investments that meet your personal criteria.
If you are just starting out in investing in real estate, congratulations to you. Put yourself together a team of an accountant, attorney, Realtor and if you need it, a property manager. Some people prefer to manage their properties themselves.
There are books to read on this subject. The worst thing you can do is go into real estate investing uneducated.
Good luck--I hope your journey is delightful.