Given the straight deck, there aren't a lot of options and flexibility is somewhat limited. For the first cycle of the day they'd spot all the planes aft where they would be fueled, armed and then launched. Once the first launch was complete, they'd bring up aircraft from the hangar deck and again spot them on the aft end of the deck, and fuel, arm and launch them. After the second launch most of your planes would be airborne so the flight deck would be prepared to recover the first launch. The landing area would be cleared and any aircraft still on the flight deck moved forward to the bow and the barrier raised and the recovery begun. The barrier was a "last resort" means of stopping a plane that missed the arresting gear to keep it from ending up in the pack of aircraft on the bow. As each aircraft lands they lower the barrier and taxi the plane to the bow raising the barrier again for the next plane. Once the recovery is complete the aircraft would be respotted aft, refueled, rearmed and then prepared for the third launch. These alternating cycles would continue throughout the flight day. For a big strike they'd launch all the planes on the flight deck while bringing up more from below that were already fueled and armed for immediate launch to get just about everything they had airborne at once. After flight ops are complete for the day they'd spot the aircraft aft and strike some to the hangar bay for repairs or to allow swapping of aircraft for the next flight day. They would position armed and refueled alert fighters ahead of the pack amidships so they would be able to launch if an incoming raid is detected. With multiple CV's they would alternate their flight schedules so that there was always a CV prepared to launch or conducting flight ops while the other CV conducted maintenance and repair.
There were other interesting ideas that were tried but most weren't very workable or effective. For instance, Enterprise had catapults on the hangar deck and the original idea is that they could launch from both the flight and hangar deck at the same time. It never really worked as the hangar deck is closer to the water so they'd be much more prone to waves entering the hangar deck plus the hangar deck was typically clobbered with aircraft being maintained or stored. You get too many planes on the flight deck and it gets too crowded which makes repositioning between cycles difficult to do so they strike the extra planes below which accounts for the crowding. Another idea was to land planes, taxi them to the bow then take them below via the forward elevator where they would be refueled and rearmed and brought aft where they would be brought to the flight deck via the aft elevator for immediate launch. Again, this was made more difficult by congestion on the hangar deck as well as the danger of refueling/rearming INSIDE the ship but this procedure was used more often than the idea of actually launching from the hangar deck.
The advent of the angled deck gives much greater flexibility but even now the Navy usually follows similar procedures of alternating launch/recovery cycles (called cyclic ops). The angled deck also lets them launch and recover at the same time but it's a very tiring process and limits the ability to do maintenance so it isn't done as a regular thing.
