Last year at this time we were looking for a new sitter and it was HARD! Then I found care.com and that made it a bit easier. This will probably only work for you if you are in a metro area (with lots of sitter options), but since it is free you can always give it a shot.
If you are looking for a sitter then you can get a free membership. If you want to access background checks, however, then you will have to pay a fee ($30 for one month, $60 for 3 months, or $120 for a year). Hopefully it will not take you longer than a month to find your sitter!
If you are a caregiver then you can advertise for free!
They do not only have information for sitters. You can find sitters, daycare providers, nannies, home health care workers, housekeepers, tutors, personal assistants, and pet sitters on the site as well.