Before buying a trading book, look at those links that have been given to you. There are free resources that you can read and search for them first before deciding to buy.
Aside from those reading materials, check on exchanges that have a demo account. From there, you will have the idea on how it looks like to trade and how much risk you're willing to take.
I don't know why most people, especially newbies, ignore this but demo accounts are a great way to practice your knowledge to have an idea about how you are doing after learning the things, if you have learned a new trading strategies, simply go ahead and use the demo account to test it out to see it if works or not, you can also see if you start trading with whatever knowledge you have gained so far to see if you will get profitable or not.
Newbies generally just invest their real money after learning a little bit about trading and that is how they incur losses, if they don't use real accounts with real money but practice with demo accounts first and learn everything properly, they won't have to face any losses when they start trading with real money.