well, I think there's a couple tutorials floating around the sites, but any answers we can give you about a specific problem will depend on the information you can give us; especially depending on how you have your UV maps set up....
Keep in mind I'm working from maya 6.5, so things may be slightly different.
But there are options in the various texture nodes for scale/coverage/etc. (note that this may not work, depending on how the rest of the model is setup). Basically click on your model, and right click into "Materials -> Material attributes". Then, click on the little arrow to the right of the "color" label and slider (this assumes that you have the bricks already created - if not, just go ahead and create the file texture before this step). Next, the attribute window should switch to display two tabs - one is the file tab, which should have popped up on top. The other one, the 'place2Dtexture1' tab (assuming you haven't renamed it) is the one we want - click on it. Among all the options, there should be two boxes next to the label 'repeatUV' - these should be one by default. Change either one (or both) to something larger than one - the texture should repeat more times, thus making the bricks seem smaller.
Unfortunately, the problem with this method is that its effectively just messing with the way the program pulls the data from the texture file - its simply making the texture repeat multiple (or partial) times over the same UV space. So if you've messed around with the mapping a bit, this probably won't work. If you have a simple, flat wall, you should be fine... but other than that, you're most likely either going to have to tweak the uvs, or change the texture insidea an image editing program.

ehhhh.... does that help? or can you provide us with new data so you can be helped better?