1

No need to book anything before you leave. Sometimes you may need to book buses the day before, or a few days if it is a busy route during high season.

2

Yes, nothing to sweat about, just watch the holiday weekends. You'll get lots of ideas about routes and buslines from your fellow travelers in the fullness of time Grasshopper ;)

3

Buses leave every hour between most major destinations. Some are more comfortable and faster than others, but you get the idea: you'll have plenty of options.

International flights are pricey, but when it comes to getting around within Peru or Bolivia especially, there are great domestic carriers and the flights are cheap since they're geared towards local travelers. A $60 one-way ticket in Bolivia will cut a 19-hour bus ride on dangerous roads to a 40-minute hop with beverage service and free lunch. You can usually get tickets on 2 or 3 days' notice.

4

Busses are the best way to travel all over South America for three reasons:

• there's good network and you'll always find connections wherever you go
• they're cheap and there're different classes with different price range
• you see the landscape and the countryside

It's never a problem to get a ticket. You don't need to prebook or purchase in advance (with only few exceptions, like carnavals or religious holidays).

The downside is that distances in South Am are sometimes huge. Bus trips that last 12-16 hrs are the average, 20 hrs and more isn't unusual. It depends partly on the country, but busses are generally very comfortable, especially in Argentina, also Chile and Brazil.
Some people travelling on tight schedule use flights thinking that it's faster way of travel. It isn't always the case. There're only few connections between provincial cities, and most flights go via capitals, with stopovers (meaning losing time).
There're also trains, but only very few lines. They aren't connected into network. Some countries don't even have a single train line.
On busses you can travel day and night time, saving travel time and money on accommodation. Cama busses (sleepers) are very comfortable, with almost fully reclining seats, food being served on board, and generally service like on planes.

5

Thank you very very much for this advice, just needed a bit of a push in the right direction. I'm spending 6 weeks in Cusco to begin with so I'll aim to book the some from there but I know I'll enjoy the spontaneity of deciding as I go a lot more. Any routes people could recommend from Cusco through Bolivia?

6

Just do a search for routes, there are loads of them on here.

7

Just do a search for routes, there are loads of them on here.