How can I use excel to create a multiple IF function?

view story

http://superuser.com – I have a spreadsheet comparing numbers of programmes sold by my company. I want to create a formula that will total several variables. In one column I have the month then whether it is a "Finance" or an "Enterprise" programme, then I have the number of minutes sold. I want to create a formula for each month telling me how many minutes of each programme were sold. e.g. in September we sold 200 minutes of Enterprise programmes. How can I create a formula to do this when 3 columns are involved? (HowTos)