It would help if we knew what kind of replication it was & if it was a push or pull subscription. I'm going to make some massive assumptions here & say that your using the following, which i think the the most common replication setup:
- transactional replication
- push subscription
- distributor running at the publisher
1. Create a schedule to create the database snapshots
If you look at the SQL Agent jobs at the distributor you should see a job that's named something like this:
In addition, it will be in a category called REPEL-Snapshot.
When you setup replication you would have been given an option to run the snapshot on a schedule. If you chose to do so, you should see this under the schedules, otherwise you'll probably see a one-off schedule in there that's not enabled from the last time you ran a snapshot. Leave this schedule alone and create another one to your liking.
2. Re-initalize subscriptions
This will re-initalize a publication for all subscribers. You can create a sql agent job to run this whenever you like. For more details check msdn.
exec sp_reinitsubscription @publication = 'publication_name', @subscriber = 'all'