minor: adding some more instructions for building from source

README.md

@@ -37,12 +37,26 @@ is the most probable location.
 
 ## Installing from source
 
-Make sure you have a recent version of go installed. Hugo requires go 1.1+.
+Pre-requisites:
 
+* Git
+* Go 1.1+
+* Mercurial
+
+Building locally (for contributors):
+
+    # install go dependencies
+    go get github.com/howeyc/fsnotify
+    go get github.com/spf13/hugo/hugolib
+
+    # clone and build
     git clone https://github.com/spf13/hugo
     cd hugo
     go build -o hugo main.go
 
+Building directly from Github:
+
+   go get github.com/spf13/hugo
 
 ## Source Directory Organization