how do I make a contact sheet?

select the photos and print - In the print layout options select contact sheet = then you can select margins and number of columns and types of captions to meet you nees

LN

Just an add on: If you want to sort the photo's manually select View - Sort Photo's - Manually

What version of iPhoto do you have? With iPhoto 9.6 select the photos you want on the contact sheet and type Command-P to start a print process. In the Print window click on the Contact Sheet layout. Then you can select the number of columns and, under settings, select what information to print under each photo:

You are welcome

LN

Great tip!!! (no printer registered, so no printing option available)

Then I guess you have better get a printer.