Update README

README.md

@@ -6,3 +6,30 @@ __kgrader__ is a code autograder, originally created by the course staff of
 Honors) at the University of Illinois to grade student homework submissions.
 
 It is written in Ruby.
+
+Installation
+------------
+
+Download kgrader over git:
+
+    git clone https://github.com/earwig/kgrader.git kgrader
+    cd kgrader
+
+If you want to use UIUC-specific assignment specifications (requires special
+permissions, but you have those if you want to grade our assignments, right?):
+
+    git submodule update --init
+
+Usage
+-----
+
+kgrader uses rake as its command-line interface.
+
+To do some basic housekeeping:
+
+    rake clean
+
+To restore kgrader to its factory defaults (i.e., delete checked-out student
+repos and any uncommitted grading attempts):
+
+    rake clobber