Soyuz has a bus every 15 mins or so between Lima and Ica. They stop just outside Pisco on the Panamerica. You then need to take a short ride in a taxi or taxi tico to your hotel.
Soyuz bus are reasonably comfortable and cost a fraction of what Ormeno charges. We paid 14 soles from Lima to Pisco and 15 soles from Pisco to Lima (market day apparently). That was in 2005.
The trip takes between 3 and 4 hours.
Soyuz offices and terminal in Lima are at corner of Mexico 333 & Paseo de la Republica
If you are looking to go to the Ballestas Islands from Pisco you can save some money by booking your boat tour in Paracas (where the boats leave to go to the island). The cheapest way to get there is to take a combi. It's much more exciting than a taxi or a tourist bus, and it gives you a good glimpse of how the locals live. Our combi dropped off workers at a few fish factories along the way.
Catch it on the street just east of the market. It should say "El Chaco" or "Paracas" on the combi (most likely you'll hear someone yelling it before you get a chance to look).
See what the ride will look like in my videos section.
Coming from Lima is very easy to reach Pisco by bus, which is the next city from Lima (at about 230/250Km). there are a lot of companies offering such service, but i would definitely suggest you to pick "Ormeno" which is the biggest, the oldest, the most satisfacting one, altough is not the cheaper...
The way is 4 hours long and it would costs 40 soles.
You can book your seat by your own, but keep in mind to give them a call or visit their offices at least a day in advance.
Getting to Pisco is a breeze. Just take one of the many buses from Lima. They charge about $1 USD per hour traveled.
Now, getting to the Islas Ballestas and Paraca peninsula can be tricky. You have to get a tour. It's best not to buy the tour from your hotel/hostel (trust me). The cheapest and more convenient option is to purchase it from one of the many travel agencies around the main palca (Plaza de Armas). These companies offer the same tour as the hotels at about 2/3 of the cost! It's the same tour! All the companies have the same boats and vehicles! In fact, it's as though it's one giant company that sells it's services to the hotels and travel agents. So you can end up spending hundreds of soles or just a few soles for the same service! Game of the town is to shop around for the best deal!