You should be able to use the MAX232 to wire between the ATmega328 and the PC.
You can test the MAX232 with a loop-back test.
If you run a terminal emulator on the PC, and turn off local echo, and link pins 2 and 3 of the 9 way D connector, you should see what you type, but not if the pins aren't linked. That proves your terminal emulator is working.
You then link up your MAX232, with all its capacitors, with pins 7 and 8 to the pins 2 and 3 of the 9 way D connectors. (I can't remember whether pin 2 or 3 of the 9 way D connector goes to pin 7 of the MAX232). Pin 5 of the 9 way D connector is ground and is connected to pin 15 of the MAX232
Then you do another loopback test. If you link pins 9 and 10 of the MAX 232, you should see on the terminal emulator what you have typed, but not if you don't link them. If that works, your MAX232 is working correctly.