You can change 2 type of fonts...

The text edit window font is easy to change:

From the Window menu select:
Preferences -> General -> Appearance -> Colors and Fonts

The open the Basic section and select Text Font (the last entery in the Basic section)
Click edit and make your selection



To change the Font in the Explorer windows, it is a little harder:

You have to navigate to where Ellipse is installed and edit a CSS file

Font size for Eclipse explorer:

<Eclipse Install Dir> -> plugins -> org.eclipse.ui.themes_(version) -> css -> e4_basestyle

(on the Lab Machines this path is: C:\Users\Administrator\codereadystudio\studio\plugins)

Add this to the end of the document, and restart eclipse

Tree {
     font-size: 16px; /* <-- Desired font size */
     font: Consolas;  /* <-- Font you want to have */
}