Typos

Closes GH-557.
Closes GH-539.

doc/node.1

@@ -36,7 +36,7 @@ Execute without arguments to start the REPL.
 .SH DESCRIPTION
 
 Node is a set of libraries for javascript which allows
-it to be used outside of the browser. It is primarally
+it to be used outside of the browser. It is primarily
 focused on creating simple, easy to build network clients
 and servers.
 

lib/buffer.js

@@ -122,7 +122,7 @@ function Buffer(subject, encoding, offset) {
         break;
 
       default:
-        throw new Error('First argument need to be an number,' +
+        throw new Error('First argument needs to be a number, ' +
                         'array or string.');
     }