It's actually fairly straight forward:
load data local infile 'billpayments-payments.csv' into table payments
fields terminated by ','
enclosed by '"'
lines terminated by '\n'
The above assumes that your fields are terminated by a comma (some programs like OpenOffice change this to a semi-colon ;) and that they are enclosed with "
The above will insert the data from billpayments-payments.csv into the table payments.