Using an Arduino board to program?

Hello All!
I'm a noob to programming Arduinos and I have a few simple questions;

1.) After programming a ATmega 328 with the Arduino board and Arduino IDE can I physically take out the ATmega 328 for use in a circuit? If so, do I need to provide an oscillator?

2.) If buy additional ATmega 328's to program with the Arduino; Do I need to buy 'ATmega328's with Arduino Bootloader' or will any ATmega328 work?

Thanks

Yes you can remove the processor, you need e few external components, the 16MHz crystal or ceramic oscillator, a couple of small capacitors and a resistor or two. Try to google standalone arduino or breadboard Arduino. That should give you the recepie.

You can by a new processor either with the bootloader burned already, or you can burn it yourself, but that requires something to burn it with like the AVR ISp or similar.