Experience gives the best lessons to traders, which beginners should never be in haste or be so confidence to trade with big amount of money by only gaining knowledge from reading books about trading.
Undoubtedly, guides and lessons learned from books or anywhere can't make you as good as practice can. This is why they say, "practice makes a man perfect." you can only become better at something if you do it yourself. Theory is important to make you understand and know certain things, but you will only become better at doing that particular thing if you keep doing it yourself.
However, regarding trading, what I said above doesn't have to be taken too literally. When you get into a financial market, you need to learn everything first, and then you should start practicing it to have some experience, but you need to make sure that your practice isn't costing you a lot of money.
A lot of newbies make the mistake of spending a lot of money on their initial investments as a trader when they aren't even completely fluent in the field, the result of that is surely them losing their money or at least a portion of it. The right way is to start with small amounts as a beginner and build your way up. Once you are experienced and fluent enough, then you can start increasing the investment amounts.