Downloading is normally done at 4800 baud, 8 data bits, no parity, 1 stop bit but there should be no need to know that, the Programming Editor configures the serial ports to how it needs to use them.
To send and receive from a PC to PICAXE; 8 data bits, no parity, 1 stop bit, and whatever baud rate is specified in the SERIN or SEROUT comamnd, 4800 baud for SERRXD and SERTXD at 4MHz.
Is there a specific problem you are having or need help with ?