My dad got into day trading a while back. He was losing money like crazy at first, but got better. Started breaking even after about 6 months. Starting making enough to live on after about a 1 year.
It seems that you need a very large amount of money that you're willing to lose while you're learning. The fake trading sites don't work because the emotions you have are different when dealing with real money.
I agree with the lots of capital to start with. When we were taking new traders on at my old job we wouldn't let them start until they deposited at least $25k into their account and then they were limited to 100 lot trades for a while until they got the hang of it.
What's scary is that the firm we were working with allowed people to leverage up to 50:1 intra-day and 10:1 overnight. When things go right, they go well... but it's also very very easy to go belly up with that kind of leverage, which happened quite frequently sadly.
One story that sticks out was this one guy who had a couple million in his account. He was using a custom program to automate his trades(self-written... like a fool), and while he wasn't paying attention got stuck in a loop and kept on shorting a single stock over the course of a few minutes. Before he could realize what was going on, he was short ~40k shares in one stock and ended up wiping out over half of his account in the course of the day trying to get out of all his positions.