add install instructions

@@ -33,6 +33,16 @@ quality as well as the responsiveness of encryption.
 Actually i must confess that i have no really clue what a random number makes
 it cryptographically "good" and i would be happy to get some feedback on this.
 
+### Build and install
+
+You can build and install this module as follows:
+
+    cd mod_entropy
+    ./bootstrap
+    ./configure
+    make
+    make install
+
 ## Requirements
 
 ### Add **cap_sys_admin** to apache.