What now, you are wandering where I start in looking for a camera or complete system that will secure my family or possession. Stop, take a deep breath, and make clear that it is not a decision to take lightly, you have to think about what you want and/or need, and then do some research. People have suggested me repeatedly that I have the best prices for what is out there, but you need not worry about price at this time, quality and customer service is what I specialize in and that is a major focus of on my business.
As technology has advanced video equipment has become quite easy and not with high price to use making it a popular selection for home security and for use in surveillance by many private investigators. Many countries worked in developing systems as a result of terrorist bombings in the early days. Now there are closed circuit bullet camera equipment in many bus stations, public areas and apartment buildings. It used in some countries has shown to have reduced the amount of crime in parking lots and still crimes against taxi drivers. Initially, make clear with your local government as to the licensing requirements for private investigators. In many countries, licensing is demanded by some states but not others.
As far as training is concerned you could get a basic skills course at some schools while these are few and far between. Doing time with an existing firm or established 16 channel dvr is usually your best even if you have a background in law enforcement. On the job training is hard to beat and during your apprenticeship, you will pick up on the ins and outs of the field. Possessing basic computer skills will be a big plus in your favor. Online investigations have become an integral part of the cameras systems business as well as the ability to write reports.