no, Staples will most likely not have the adapter you need.
The types of stores which *might* have the adapters you need will be "Authorized Apple Resellers"... Fry's Electronics, CompUSA, AppleStore among others - call them befor you go to see if they have what you need...
Typically, the projectors can connect a bunch of different ways. The most common method is using a VGA cable. However, most projectors also have S-Video and RCA-composite video in, too. The specs at http://www.apple.com/macbook/specs.html under "Graphics and video support" indicate:
VGA output using mini-DVI to VGA adapter (sold separately)
Composite and S-video output using mini-DVI to video adapter (sold separately)
That means the adapter you get needs to connect to your MacBook mini-DVI port and one of those... Of course, which connection method you choose will depend on the way the projector is "installed".
If projector is just brought in and placed on a table-top and pointed at a wall or screen, then it is not installed and any of the three connectons methods are possible if you get the right adapter for your MacBook. There is likely already a VGA cable with the projector, so yu would not need to worry about that if you use that adapter. If you decide to use the other adapters, you will also need to bring a cable - either the S-Video (which is the same as the old Apple Desktop Bus cables that used to connect the mouse and keyboard in the old days before USB) or an RCA (male on both sides) cable - again, depending on which adapter you get.
Whichever adapter you get, it should be around $20.
I need to hook my macbook up to a projector at school so I can do a presentation. I took my macbook in yesterday to hook it up, just to be sure it would work okay, but the cord on the projector was not right.
Is there anyway I can buy an adapter to make them connect? The projector's cord is the same kind a PC monitor has.
Would I be able to find one at an office supply store (like Staples)?