SPOILERS!
In the first four books written by Christie Golden they are in the Alpha Quadrant. However, of all the crew, we basically only have Captain Chakotay and Lieutenant Harry Kim aboard Voyager. All the other characters are new on the ship (our main characters are in different places, Janeway is an Admiral, B'Elanna and Tom are on Borath (sp.?) trying to find out about the Kuvah'magh ... etc.)
Next comes that horrible TNG book called BEFORE DISHONOR, in which Janeway becomes the borg queen, then later a Q ...





Then in the fifth Voyager book - from then on written by Kirsten Beyer - they (and eight other ships) prepare to go back to the Delta Quadrant. With slipstream, it only takes a little more than two hours ...



Ambassador Neelix welcomes them at New Talax from HOMESTEAD.
They are sent back on a three-year mission basically because the borg do seem to have vanished but Starfleet is unsure if that's the case or not. So they send back the Voyager fleet to investigate. The fleet is under the charge of Admiral William Batiste and Captain Afsarah Eden (husband and wife - a little piece of information for those who are not sure if husbands and wives can serve together or not).
From then on, they end up becoming part of different adventures while the main mission remains: quest for the remains of the borg.