How was exploration affected by the invention of the printing press?
The printing press had enormous effects on human society; as seminal technological advances go, it's right up there with writing, the computer, and the steam engine, just a tier below fire, the lever, and the wheel.
The printing press made it possible to copy writing quickly, accurately, and cheaply; this meant that transferring information from one place to another, or sharing it with a large number of people, suddenly became much, much easier.
It's probably no coincidence that the printing press was invented around the same time as the Age of Exploration began; printing changed the economics of long-distance trade a great deal.
The ability to carry information reliably over long distances (along with some other advances in monetary policy and accounting methods during the same period) made it easier to keep track of business transactions involved in overseas trade.
Stories about glorious adventures overseas (many of them completely false, but how could people know that unless they traveled themselves?) could also be printed and sold in mass quantities for the first time, drumming up public interest in missions of exploration not to mention being themselves a source of profit.
The printing press also had more indirect effects that may have been even more important; by increasing literacy and improving education, printed books also contributed to the advancement of science and technology, including technologies such as sextants and chronometers that were vital for safe, reliable navigation across the oceans.