Help with motor control( first timer)

I am just having a little trouble visualizing how I am going to solve this issue, if it even is an issue. I am trying to make a mobile robot that will carry my sensor module. It will have four wheels, and therefore four of these motors : http://www.robotshop.com/ca/en/vex-2-wire-393-dc-gear-motor-motor-controller-29.html.

These are rated at 7.2V. How would I go about powering these? I have a 7.2V lipo battery. I know that if I plug the battery in through the DC jack, i can access the voltage using the vin pin. But would having the battery power the arduino and the four motors be too much? I am assuming in this case, I would use a seperate battery for the four motors and a battery for the arduino.

How would I split the battery(which only has two wires, red and black) into 4(sets of) wires for the motors? Sorry if this is a stupid question, and is this a good method to power the motors?

If your battery can drive 4 motors, it won't even notice the Arduino. Arduino doesn't draw as much by comparison.

For splitting, you can use a PCB (or perfboard), or just twist the wires together in a mass and heatshrink. Or use something like a 4-way splitter intended for quadcopters. Such are available from quadcopter hobby supply places, for example HobbyKing and others.

But you will in any case, almost certainly have a motor driver chip/board/shield in the works, so it's likely you will provide the voltage to that (or those, if you need 2 for 4 motors), and then take the power from the appropriate pins to to the motors. Beware of voltage drops; depending on the board/shield/chip you'll lose maybe 2-5 or so......