Arduino Mega - Serial to DB9 plug wiring

slpefanis:
Thanks for all the feedback. This is for an assignment, and the RS232 comm is between two units. if the comms aren't to a PC, will i still require a inverting transceiver?

Would something like (http://littlebirdelectronics.com.au/products/pololu-23201a-serial-adapter-fully-assembled) be suitable?

Your first post shows wiring to arduino pins, so how can this be comms between two RS-232 units? Again if you want a accurate answer you need to provide more details about the specific type of 'units' to be wired together.

The module you linked is a good RS-232 to TTL serial converter and may be part of your needed solution.