Would I be able to change an option in the Arduino IDE to make it use the printer port?
"Converting" a parallel port to nine-pins is absolutely positively not
going to work.
In the middle right of the board is a six-pin header labeled ICSP. This can be used to program the processor "directly" rather than through a computer's serial port using the bootloader. I believe this can be done through a computer's parallel port. This is something typically done by an experienced Arduino user. If you're new to Arduino, I suggest getting everything working using a serial port first.
But, even if you use the parallel port + ICSP to program your board, you'll want a serial port so you can debug the program.
If not can I get a serial to usb adapter and will it work alright?
Yes. I've been very pleased with this...http://www.usbgear.com/computer_cable_details.cfm?sku=USBG-232FT-1&cats=199&catid=626%2C106%2C199%2C465
Warning: It ships with a very buggy driver. Get the latest driver from FTDI (or Microsoft).
But you only need a single serial port not a dual serial port. Something like this is more appropriate...http://www.usbgear.com/USB-PRODUCT-DETAILS.cfm?sku=USBG-232MINI&catid=&cats=