Install tarsnap. Then, here's some stuff.

backup.sh

#!/bin/bash

NAME="something"
d=$(date "+%F--%H-%M-%S")
/usr/local/bin/tarsnap -c --keyfile /root/tarsnap.key --cachedir /usr/local/tarsnap-cache -f $NAME-backup-$d /etc /home /root /var

crontab.txt

0 0 * * * /root/backup.sh > /dev/null 2>&1
30 0 * * * /root/prune.py > /dev/null 2>&1

prune.py

#!/usr/bin/env python

name = "something"

import datetime
import subprocess

def exc(cmd):
  p = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
  stdout, stderr = p.communicate()
  if p.returncode != 0:
    raise Exception("Command failed with " + stderr)
  return stdout

backups = exc('/usr/local/bin/tarsnap --keyfile /root/tarsnap.key --list-archives').strip().split('\n')

backups.sort()
backups = backups[:-10]

month_ago = name + "-" + (datetime.datetime.now() - datetime.timedelta(days=30)).strftime("backup-%F--%H-%M-%S")
for backup in backups:
  if backup < month_ago:
    print "Deleting", backup
    exc('/usr/local/bin/tarsnap --keyfile /root/tarsnap.key --cachedir /usr/local/tarsnap-cache -d -f ' + backup)