I have no idea how to write test classes for batch apex. Or for any apex for that matter.

I have looked at the documentation, but I do not understand what exactly is going on. Does anyone have any tips on how ot learn Apex without taking the class? This is really frustrating for me.

Here is my apex batch class. I have a few that are fairly similar ot it, but none have test classes.

global class countRefContacts implements Database.Batchable<sObject>{
	global final String gstrQuery = 'select ID, Number_of_Reference_Contacts__c from Account';
    global Database.QueryLocator start(Database.BatchableContext BC){
		return Database.getQueryLocator(gstrQuery);
    } 
    global void execute(Database.BatchableContext BC, List<sObject> scope){
 		List<Account> listAccount = new List<Account>();
      		for(SObject objSObject : scope){
				Account objAccount = (Account)objSObject;
				Integer intNumberOfRefs = [SELECT count()FROM Contact WHERE AccountID = :objAccount.ID and Email != null and Binary_Reference_Contact__c = 1];
			  	if (intNumberOfRefs <> objAccount.Number_of_Reference_Contacts__c){
			  		objAccount.Number_of_Reference_Contacts__c = intNumberOfRefs;
			  		listAccount.add(objAccount);
			  	}
		    }	         
       if (listAccount.size() > 0 ) {update listAccount;}
    }
    	global void finish(Database.BatchableContext BC){
    }

}

Here's what i have so far. I dont know what goes in between Test.start and Test.StopTest.

public class testCountRefContacts {
	static testMethod void testCountRefContacts(){
	List<Account> accns = new List<Account>();
	for (Integer i = 0; i<200; i++){
		Account a = new Account();
		accns.add(a);
	}
	insert accns;
	
	Test.StartTest();
	countRefContacts count = new countRefContacts();
	ID batchprocessid = Database.executeBatch(count);
	
	Test.StopTest();

}
}