First of all, I advise you to choose sites of bookmakers that have been around for a long time and have a good reputation. For example, here ?????
I found a lot of useful information about sports betting. I found here a description of the betting strategy and information about official and safe sites in order to invest money in it. Also on such sites there is information that will be useful to you when you will make your forecast for a game. It seems to me that such potals very much help to understand this and make a profit, not to lose the entire deposit.