jjmuteteke:
I would like to thank every body for helping me you all just literally saved my life but i have one more quick question so do i use schematic by cr0tch and if i do do i need the diode?
You should use the diode if you want the transistor to live for any reasonable amount of time. This diode prevents what's called "flyback voltage" (caused by the collapse of a magnetic field in a coil - as in the case of a motor) from back propagating through the transistor, which can break it. The voltage generated is generally much, much larger than the supply voltage. IIRC, the 1n4001 is good for about 50 volts, which is well within the range of what your are working with (if you want to be "doubly sure", sub in a 1n4004, which is good up to 400 volts).
See also this wikipedia article on flyback diodes: Flyback diode - Wikipedia
jjmuteteke:
also based on the schematic i don't need to give the motors(4 of them) their own 9v battery?
Well, technically no - you only need one 9 VDC source. With that said, four of those motors running off a single PP3 9 volt battery is going to run that battery down to nothing in no time flat. You really want to use a better source for the entire project (something based on AA cells, minimum - if sticking with alkaline/NiCd/NiMH - otherwise you are looking at having to use a lithium-based battery, and all the potential recharging hassle/expense that can entail).
jjmuteteke:
also im going to go to radio shack so can i get the final schematic on wether to use the diode or not? also for the programming want to control the speed of motors so can i get the programming on that based on the PWM pin nine on the arduino duimilanove ATMEGA328.
I hope I've answered the question; but you are free to wait for any second opinions, of course (I'm certainly not one for thinking I'm the last word on any topic).
As far as the PWM control is concerned, just hook the circuit to the pin for the PWM control, and use the analogWrite() function to control it (see the Fade sample code/tutorial - or any other of the myriad tutorials for motor speed control using PWM for the Arduino out there).
jjmuteteke:
thank you very much for your help
Good luck, and have fun! 