For new traders that are eager to jump into the markets there was a really important point made that I don't think can be stressed enough:
"Open a trading account with a broker that offers a simulator, so that you can practice trading using virtual money."
Have had clients not listen and jump straight into trading and loose way more then they should have even invested in the first place. Practice, review results, practice some more, review again, and keep repeating this.
Also understand all the taxes you will owe. Taxes can really effect things based on where you live.