Refer to CENTRALIZED TIME TABLE (BUS STATION-WISE) updated by APSRTC authority.
Know the frequency of bus services at From and To locations.
Refer to APSTC home page for more details. You can also register with APSRTC online portal (similar to irctc.in) to make advance bookings. However, the portal isn’t useful as it doesn’t suggest the places and whatever you enter is shown up as invalid .