first of all, I really wouldnt recommend doing anything at your panel if you have no electrical experience. hopefully you already have a 20a double pole breaker ready. Make sure you use a double pole so that both the hot connections are disconnected if it trips.
220v is going to be 3wire, 1 red 1 black 1 white (and a bare ground wire, but that doesnt count as it is not considered a current carrying conductor, however it is important)
the voltage between the white and red = 110
the voltage between the white and black = 110
the voltage between the red and black = 220
pull the wire from the 20a double pole breaker through the knockouts on your first receptacle box, giving yourself 6"-9" of wire, tighten the wire down so it is secure but not being pinched. strip the insulation off the 6" wire with a knife and about a half inch off the end of each wire with some strippers. connect the bare ground to the green screw on the back of the box and to the receptacle if there is a green screw on it.
connect the red to one of the bottom screws and the black to the opposite bottom screw. do the same to the top 2 screws keeping the same color wire on each side, and run that top connection to your next receptacle and repeat. Tug the wires fairly hard (dont twist though) to make sure you have a solid connection everywhere. You will simply maret the white wires together, as they do not need to be connected to the receptacle for 220v, again, tug the wires after mareting them to make sure they are all conected well. Not sure what your local code is in terms of number of 220v receptacles per circuit
but in europe they use 220v exclusively in residential and in most areas they are allowed 6 receptacles per circuit from what I have heard. The reason they use 220v is because it is more efficient, as the higher the voltage the less current, thus longer runs with less loss. Same reason the power companies distribute power at ~500,000volts across the country.
