This is a long shot, but could it be the Outernet series by Steve Barlow.
A wild ride through strange galaxies and unexpected adventures. But watch your step -- and don't step in anything gross or smelly along the way!
The Outernet is a web of intergalactic computer networks linked through Servers on different planets. As the series opens, we discover that the evil Tyrant and his henchmen (the FOES) are trying to take over the Outernet and use its powers to control the galaxy.
Our heroes, including several not-so-lucky Earth kids, accidentally connect to the Outernet via a lost Server. They must work with the Friends of the Outernet to keep freedom and liberty in the Galaxy. They are assisted (and often hindered) by a hilarious dog and cat team who are disguised agents of the Friends and the FOES.
The first book was published in 2002, so the date matches, there are six books in the series, and the third book of the series is indeed called Odyssey.
We are not alone. We might wish that we were... But we're definitely not. As Jack, Merle, and Loaf have discovered, there is life on other planets -- and lots of it. In fact, they're planet-hopping as they try to keep the Server safe from the FOEs. And they keep meeting all sorts of ALFs (Alien Life Forces), including creepy spider things on Planet Arachnus. The kids' mission? To find the "genius" who created the Outernet. But with the bad guys hot on their cosmic trail, the mission gets sidetracked. And now they're journeying to different galaxies. Galaxies far, far a -- well... you get the drift.