Matlab is software used for scientific computation and is one of the foremost used software products in academia and engineering. It offers a host of tools and has had years of support. In the lab, we use it to analyze electrophysiology data, behavioral data, run statistics, build neural networks, and a lot more. At some point, you will definitely hear about it, if not use it yourself.
If programming or data analysis interest you at all, then take a look at the document below, it is a great intro to Matlab Doc.
Wait, what is that you say? You can't open the file because you don't have Matlab? Almost all of the lab computers have a copy of Matlab, and if they don't then let someone know! To start it, search for MATLAB in the start panel (or search in in ubuntu). Say you want to crunch some numbers in Matlab, but you don't happen to be in the lab, if you are a student at IU then you get your own free copy that you can download on your own computer. (Which is great considering how expensive it is). Just go to IU Ware and search for Matlab on your specified OS, or go here. The instructions to download it is on the page.
Tutorials:
Mathworks offers fantastic tutorials to learn how to use their software and in addition, they maintain the documentation for reference (here). There are also some great tutorials here.