You can go to azgfd.org (Arizona's Game & Fish Dept. website) and you can find the stocking schedule there. There's alot of good information on there!
BEST URBAN FISHING Phoenix 2006 - Red Mountain Park
City anglers can get their daily fix of aquatic sport during year-round urban fishing at Red Mountain Park. The eight-acre oasis features two fishing docks and waters stocked every two weeks from September through July with hybrid sunfish, largemouth bass, carp, white amur, and tilapia. The 17-foot-deep lake is also stockpiled with rainbow trout during the winter months and channel catfish in the spring and fall. If the fish aren't biting, explore the 1,146-acre park featuring four basketball courts, walking trails, volleyball courts, soccer fields, shade-providing ramadas, or the adjacent Red Mountain Multigenerational Center. A class U Urban Fishing License costs $16, or a one-day pass costs $12.50, and the park is open from dusk to dawn. Go fish.