Manzanillo's airport has just one runway and is connecetd to various mexican cities and a few in United States, it is very close to the pacific ocean so when you are landing you'll get a nice view of the sea, the beach and the forest surrounding it. It is quite small and doesn't have a lot of traffic.
In this place you'll also appreciatte the coexistence between humans and nature, both when we arrived and when we left the aisles and rooms had some crabs walking around with no worries, wich is a curious and nice sight. They probably felt attracted to the air-conditioned to escape from the high temperatures outside, and they surely came from the ocean.
The airport is very close to Jalisco and a bit far away from the city, it will take you around one hour to arrive by car to Manzanillo, almost the same duration of the flight from Mexico City.
We flight by a small airline called Magnicharters, and we were very pleased with their service, also if you are not into independent travel they'll arrange you a packcage, and they have nice and prepared guides.
Researching intercity buses between Manzanillo and Zihuatanejo didn't turn up very many options. Lots of buses travel to Guadalajara or to Puerto Vallarta, but down the coastal highway there's only one bus company (Elite) and they offer the service three times a day (6:30 am, 6:30pm and 9:30pm) for 216 pesos (in 2008). These buses are actually continuations of service starting further up the coast, so the chances of departing on time are just about non existent. Still, you have to show up on time, just in case and I chose the 6:30am departure for the eight hour trip.
It turns out we left an hour and a half late and I was happy just to be on the bus heading south. There are almost no buses along the route so the Elite bus stopped for pedestrians standing by the side of the road. The driver charges 10p (US$1.00) per person for these pickups and the passengers sit in the first couple of rows of the bus until we get to the next village. It’s hard to begrudge ether the pedestrians or the drivers for this practice, but it does slow the trip down a bit. The road tends to wind along the coast and in spots you know you're gong too fast around corners that are clinging to the cliffs.
About noon, we stopped at a cantina for lunch. The driver said we be stopping for 30 minutes, but I guess my Spanish is a bit rough because we didn't leave for an hour and a half. The other interesting point was that we changed drivers. I hadn't noticed, but beside the luggage compartment under the bus was a cubicle where a spare driver had been sleeping. A couple of hours later, as we were coming down out of the hills, the bus started limping along because something had happened to the clutch. Fortunately, we were just coming into the first major city of the trip and so we checked in at the bus station. They sent us to a garage to get fixed but the garage couldn't do much so close to the end of the day, so we went back to the bus station and boarded the next bus to Zihuatanejo. Fortunately, from this point south, buses were departing for Zihuatanejo every two hours, so we didn't have long to wait. After all the delays, we finally arrived in Zihuatanejo about twelve hours after departing Manzanillo.
The beaches in Manzanillo are beautiful and surprisingly devoid of people. I chose to stay in a hotel along the beach but wanted to visit the downtown area. Fortunately, as with most of the Mexican coastal cities, Manzanillo has a main drag that parallels the ocean and local buses are frequent and inexpensive. For 5p (US0.50) you can enjoy a half hour ride from the beaches and reach downtown (or vice versa). Look for "Centro" on the windscreen of buses pointed downtown (just about every bus) and for the return trip look for Miramar, which goes the entire length of both beaches.