It's finished when you have a disaster and recovery plan. If you don't have everything being backed up in some way, you're just running programs and waiting for them to die, or for accidental mistakes to be made and data to be lost.
At the beginning, this can be simple as a 3 or 4 line script that compresses all your files, dumps the database, and copies it offsite, which you run on a daily/hourly basis.
Seriously, if you're not running backups and testing them, you're not done. It's unbelievably cheap insurance.
We started doing informal "keep this in each of our houses" off-site backups on simple burned discs from our first week, and bi-weekly dumps to Iron Mountain a few months later.
Spend some time making sure the backups actually work. We found errors in our source repository that we had to write tools to fix, but since we budgeted some time, it wasn't a big deal.
At the beginning, this can be simple as a 3 or 4 line script that compresses all your files, dumps the database, and copies it offsite, which you run on a daily/hourly basis.