Fix a small typo and remove trailing whitespace.

docs/validate.rst

@@ -14,8 +14,11 @@ The simplest way to validate an instance under a given schema is to use the
 
 .. autofunction:: validate
 
-To learn more about creating json schema to validate your data, see 
-`Understanding JSON Schema <http://spacetelescope.github.io/understanding-json-schema/>`_
+.. [#] For information on creating JSON schemas to validate
+    your data, there is a good introduction to JSON Schema
+    fundamentals underway at `Understanding JSON Schema
+    <http://spacetelescope.github.io/understanding-json-schema/>`_
+
 
 The Validator Interface
 -----------------------
@@ -184,17 +187,17 @@ implements.
 
 .. autoclass:: Draft4Validator
 
-For example, if you wanted to validate a schema you created against the Draft 3
-json schema, you could use:
+
+For example, if you wanted to validate a schema you created against the
+Draft 4 meta-schema, you could use:
 
 .. code-block:: python
 
-
     from jsonschema import Draft4Validator
-    
+
     schema = {
         "$schema": "http://json-schema.org/schema#"
-        
+
         "type": "object",
         "properties": {
             "name": {"type": "string"},