Microarray analysis is a very important and common part of bioinformatics analysis. It can be fairly complex and involve a lot of tools; in this case, we are going to use a simple and well integrated tool called Expression Profiler from EBI. It's relatively straight-forward and good for many forms of analysis.
In this case, we will use a tutorial written by Gabriella Rustici from EBI. It's available as a PDF. Feel free to print it out if that would make things easier for you.