For the chassis I am using 4x continuous rotation servos that have wheels (not shown in photo). More photos are available at http://builtbyben.net/3d-printing/
I am planning on using rechargeable AAA NiMH batteries to power the servos.
As for the sensors I plan to have 1x Ultrasonic Sensor to measure the distance, an Xbee to communicate with my computer/another Arduino, 1x IR Reciever diode and possibly 1x compass sensor.
I have been working on a schematic in Eagle although I apologize for any errors as I am still learning Eagle and based on your suggestions I need to change some things. The ultimate plan is to make a PCB for the project.
I have made a standalone Atmega328 on a breadboard so since I have all of the parts already, I am making this through hole instead of SMD which I recognize is the better option and the future.
Right now the servos are connected to pins 17,5 and 11 which I plan to change. The plan was to have pins 17 and 5 split so that 5 went to the left 2 servos and 17 to the right 2 but I need to change that.