I need to make a cake that looks like an old brick school building and was wondering whats the best way to make the bricks. the building is prettymuch square so I thought that I would stack the cake and cover in fondant. I'm new at this cake decorating and not sure what the best way would be..any advice would be much appreciated. thanks
First of all, Welcome to CC!!.
You can use an impression mat such as this http://www.cakeartpartystore.com/store/e-StoreOperations_viewItem.asp?idProduct=30626 to create the bricks. I'm sure there are other techniques so let's keep our fingers crossed and hope someone else would answer. 
Patchwork cutters has one that looks like a cookie cutter. Its really simple to use. I like it better than the impression mats because I always had a hard time lining them up the right way.
You should have your fondant already colored when using either one. Have it rolled out also. The cutter I use you use it once your fondant is already on your cake. The impression mats, one you can do after you roll it out and another you can use once its on the cake. Depends on which one you buy. They all come with instructions though.
If you want the one I got, you can buy it at Global Sugar Art. If you want to see what it looks like you can go to Patworkscutters.com and see what it does.
I second what Weirkd said about the brick embosser from Patchwork cutters. It is my favorite brick embosser. Make sure you apply shortening or dust with cornstarch on the embosser and fondant so they don't stick together. I personally use cornstarch but Marion Frost of Patchwork cutters recommends shortening.
Here is what it looks like from Global Sugar Art with a sample cake embossed with it: http://globalsugarart.com/product.php?id=17334
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