This area does very well with vacation rentals. The rental rate is determined primarily by the number of people the house can sleep i.e. 3 bedrooms VS. 4 bedrooms. The other factor is the age of the home and condition along with any amenities you have (outdoor shower, deck/patio, air conditioning, premium cable TV etc.).
Using the assumption that you have an average home in this location, with 3 bedrooms & 2 full baths, basic amenities and parking for 3 cars, I would estimate a ball park weekly rate of $1,750 - $2,400 if you're on the east side of Ridge Road and $1,400 - $1,950 if you're on the west side of Ridge Road. With these rates, I would expect you to book all of July & August and then if you drop the rate for the "shoulder" seasons (May, June and September, October) I would expect you'll rent a fair number of those weeks too.
If you hire a rental manager, you can expect to pay 20% +/- depending on whether they include cleaning, repair services, linens etc.
Good luck with your new venture!