[SalesForce] Has anyone created a report snapshot capability via batch apex and knows how to write a test class for this scenario

I've come across some great threads on using Apex batch and schedule classes to overcome the 2K governor limits on reporting snapshots. For an example of the model I followed, see this article:
How to overcome the 2000 row limit for analytic snapshot entry?
I've successfully created a batch class that spoofs a reporting snapshot and have functionally tested it in a developer sandbox and now want to run it in production but am struggling with getting the test class, written.

My batch class:

global class SnapshotOpenCasesBatch implements Database.Batchable<sObject> 
 {

    //Gather all the records I want to use in the execute method
    global Database.QueryLocator start(Database.BatchableContext BC) 
    {
        return Database.getQueryLocator([SELECT ID, OwnerID, Name, Case_Type__c, Subtype__c, Status__c, Reason__c, Case_Age_Days__c, CreatedDate FROM Custom_Case__c WHERE Status__c in ('New', 'Work in Process', 'Escalated', 'Solution Proposed/Validation') ORDER BY CreatedDate ASC]); // Production source field is Created_Date__c
    }

    global void execute(Database.BatchableContext BC, List<Custom_Case__c> openCases) 
    {

            //for creating new Snapshot batch.
            List<Snapshot_Open_CASE__c> newSnapshot = new List<Snapshot_Open_CASE__c>();

            //create map collection to pair case owner ID and full name 
            Map<ID, String> userMap = new Map<ID, String>(); 

            //add all OwnerId values from openCases List to the set of userIds for query
            Set<ID> userIdSet = new Set<ID>();

            for (Custom_Case__c c : openCases) {
                userIdSet.add(c.OwnerID);
            }

            //Go get all the User ID + name combos from the set of Ids created above
            List<User> userList = new List<User>([SELECT ID, Name FROM User WHERE ID in : userIdSet]);

            //Load userMap with the results of the query above
            for(User u : userList){
                userMap.put(u.id, u.Name);
            }   

            for (Custom_Case__c c : openCases) {
                Snapshot_Open_CASE__c snap = new Snapshot_Open_CASE__c();
                snap.CASE_ID__c = c.ID;
                snap.OwnerID__c = c.OwnerID;
                snap.Case_Number__c = c.Name;
                snap.Case_Type__c = c.Case_Type__c;
                snap.Subtype__c = c.Subtype__c;
                snap.Status__c = c.Status__c;
                snap.Reason__c = c.Reason__c;
                snap.Case_Age_Days__c = c.Case_Age_Days__c;
                snap.Created_Date__c = c.CreatedDate.date(); // Production source field is Created_Date__c // also convert datetime to date
                snap.Name = String.valueof(Date.today()); // Use execution date as unique id

                // add the user name
                snap.Owner_Full_Name__c = userMap.get(c.OwnerId);

                //load up the data for insert
                newSnapshot.add(snap);
                }

            insert newSnapshot;
            }

    global void finish(Database.BatchableContext BC) {
        system.debug('Batch Job is Complete');
    }
}

My unit test class:

   @isTest

public class testSnapshotBatch {
public static testMethod void testBatch() {

    // insert test data
    Snapshot_Open_CASE__c newSnapshot = new Snapshot_Open_CASE__c(
        CASE_ID__c = 'a0mE0000004oSiHIAU',
        OwnerID__c = '005E0000004e3aRIAQ',
        Case_Number__c = '114633',
        Case_Type__c = 'Machine/Component Failures',
        Subtype__c = 'Water/Cooler',
        Status__c = 'Solution Proposed/Validation',
        Reason__c = 'Quality Issue',
        Case_Age_Days__c = 257,
        Created_Date__c = date.parse('2/27/2014'), // Production source field is Created_Date__c // also convert datetime to date
        Name = String.valueof(Date.today()), // Use execution date as unique id
        Owner_Full_Name__c = 'Firstname Lastname');


    Test.startTest();

    SnapshotOpenCasesBatch testBatch = new SnapshotOpenCasesBatch();

    ID batchprocessid = Database.executeBatch(testBatch,1);

    Test.stopTest();

    System.assert(batchprocessid != null);

}

}
Most of the examples for unit tests are for triggers, and it's necessary to create test data for the trigger. In this scenario there is simply the SOQL SELECT query. What do I need to do to create the test data?