Star Wars: Outbound Flight by Timothy Zahn
Set five years after the events of "The Phantom Menace", Obi-Wan Kenobi and his young Padawan Anakin Skywalker board a massive ship called Outbound Flight, who's mission is to chart the Unknown Regions of space and colonize planets with more Jedi and Force-sensitive people. Meanwhile, in the Unknown Region, a highly advanced alien race captures a smuggler's freighter and takes three humans captive. The stories intertwine in one climactic battle that will decide the fate of everyone aboard Outbound Flight and will greatly impact the future of the Jedi.
An excellent book to begin reading inside the Star Wars Expanded Universe. There are a few references to a previous adventure featuring a missing Jedi, but are otherwise straightforward. One or two minor unresolved plot points exist, and Obi-Wan and Anakin are not present during the final battle, but it's still a good read.