newbie

hi all.
im new and would like to know how things work etc. im reading as much as pos without getting to confused.
i think with the little money i have then CFD is best for me.
im using plus500 demo since friday 20/7/12. at first just click n buy not knowing what im doing .. then started to look at the real picture, i would like to trade part time for now and hope to make small amount of profit. i know making loads of money is a big dream. i dont understand how such company makes the money.
what r the charges for using this platform.
if no charge then how do they make the money from us.
thanks
Andy

below is a sample from the site i use with demo money/
if i understand it and was using real money the figures would b

Buying: Oil
Current rate:$91.55
Amount: Barrels 2
After leverage Value:$ 183 = £117.30
Required securities: $ 15 = £9.38
Close at profit - when rate is "92.12"
Close at loss - when rate is "90.55"

i would b investing £9.38 to buy in
gainning £ ?
losses £ ?
and there be no commission to pay.
is that right and how much would "?" be
gain is .57 x2 = £1.14
loss is .50 x2 £1.00

so with the above example that i showed is it what is know as spread betting?
im planning as said before to start real money with about £100(uk) and would like to see a return something like £2 to £7 gain per day and off course i know i will lose alot to. with a stop loss at about a 1/3 of what my profit stop would be on a deal.
for an example
gain stop +£10
loss stop -£3.35
my way of thinking is 3 losses would equate to one win. so being that i dont know what im doing i hope the odds are in my favour and help me gain knowledge without losing to much money.
any advice would be great.
thanks