Before you rush to open an account, here's my advice:
Never gamble more than you can cheerfully afford to throw in the gutter. If you're playing with money you can't afford to lose, you'll 'play scared' and make emotional decisions... which almost guarantees you'll get wiped out fast.
Be realistic. Why do you want to spread bet? Many people treat it as a hobby; they love the adrenaline rush of winning (I've made £250 in less than three minutes on several occasions) and are prepared to take their losses on the chin (I've squandered £250 in less than two minutes on several occasions). If you're determined to get rich, the bad news is that it won't be easy, while the good news is that it IS possible. Spread trading, as winners prefer to call it, is a skill that can be learned. Read books. Subscribe to magazines. Take courses. Study share price charts. Practice by doing. Expect to lose before you start to win.
Start small. The harsh reality is that most beginners lose their money. But you don't have to join them. With most companies, the minimum trade is £1 a point. However, there are others, like the company I use (I confess I chose them originally because they have the best colour scheme) that let beginners try their hand trading 1p a point for the first few weeks. That's an excellent way to decide if you're enjoying yourself, without risking too much.
Specialise. Get to know a few markets really well, rather than playing the field. Each one tends to have a rhythm of its own. The people who make most money aren't random traders. They might only trade on the price of gold... or a few specific stocks... or exclusively on oil.
Manage your money. The winners I know never place more than 2% of their bank at risk on any single trade. So with a bank of £2,000, you're prepared for a maximum loss of £40. You set your stop-loss accordingly, and if you're buying the FTSE at 50p, your trade is closed automatically if the index drops 80 points.
Cut your losses - fast. One guaranteed way to go bust is to watch your trade sink into debt. You think to yourself, "It's only a theoretical loss. And the price is bound to recover." Trust me, most times it doesn't and you only end up losing more.
Don't panic when you make a profit! There's a saying that beginners run their losses and cut their profits. It's true. A trade works out beautifully... you're making £100... you take the money... if you'd waited another few minutes, you'd have made £150. Then again, there's another saying that no-one goes broke taking a profit. Have fun!