your computer needs to have the ip add. 192.168.0.2/netmask 255.255.255.0/gateway&dns 192.168.0.1
your ps3 needs to have ip add. 192.168.0.3/netmask 255.255.255.0/gateway&dns 192.168.0.1
now there are other adds you can use but since youre no network expert just go with this here.
after that fire up your ps3, fire up the ftp server, connect from your pc (using saay filezila ftp client) and start transfering.. if you have a newer lan card you can transfer arround 20MB/s depending on how fast your ps3 & pc HDD are.