MongooseJS Validation

The docs on MongooseJS can be really unclear at times, here are some pointers on validation that may help (note this is valid as of MongooseJS 1.3.3)
Making a field unique:

var User = new Schema({
email: { index: {unique: true} }
});

Note: If your collection exists in Mongo, you need to drop the collection before schema changes kick [...]