Yes, that is enough. About the only thing I would add is a separate power source for the servo as many run into problems trying to power a servo from the arduino's 5V pin. Even four series connected AA batteries would be a better way to power a servo.
How were planning on powering the arduino board? That may factor on the best/easiest was to power the servo independently from the arduino 5V pin.
But I thought that the 5v pin from the arduino should be enough to power it?
Depends on servo model, mechanical load on servo, etc. Arduino is great at controlling a servo, not so great at powering them. If only using one servo with no mechanical load and it is a low current model then maybe you will get lucky. Try it and see, but if anything strange happens remember to then try powering it externally.
Is this a common problem?
Yes, people post all the time about trouble using servos with arduino, and often it's because they are not using an external power source for the servos.
And where/what to buy the external power source?
Servo's like +5vdc power (usually rated from 4.8 to 6vdc) and one amp of current per servo being powered is a good rule of thumb. Many sources of power modules and batteries are available, perhaps the same place you got the arduino?