Hi,
Where abouts are you based? If your in the uk then putting an ad on the petcare trust website is a good idea. If your not then I can help overly much but you could try posting on this forum
www.groomertogroomer.com lots of groomers read it regularly and you may find someone through it. Other wise local job centre type places.
Just get good history on the groomer and see examples of their work - they might be qualified to a certain degree but their grooming could still be below standard.
Good Luck.