(I don't think I'll have nothing but Star Wars content this week, but I have a pretty decent amount lined up for the next week or two, so... Whatever.)
Out of all of the Star Wars Expanded Universe, the Han Solo Adventures, because of their age and matters of timing, aren't quite as well-integrated into the EU as a whole as the larger EU created after Heir to the Empire (Zahn's work is easily the best of the EU, though I could be biased-though I quite like a lot of Aaron Allston's work as well), and also don't mesh with the greater EU view of the Star Wars universe's construction (clashing even more strongly with the post-prequel retcons). But that doesn't cause them to not be worthwhile (one good bit can be found here).
The Adventures, as with the more obscure Lando Calrissian Adventures, take place in semi-autonomous regions that aren't under the direct influence of the Empire, but of some form of sub-government. (These include the Corporate Sector Authority, the Tion Hegemony, and [in the Lando Calrissian Adventures] the Centrality. All are managed as semi-independent states which answer to the Empire as vassals.) This gives the author some freedom to make stuff up for the villains rather than worry overmuch about consistency with the films or other source materials. The Corporate Sector, incidentally, is an extremely new area that has no native sapient life, and is thus being radically exploited; the Tion Hegemony is a very old region that's fallen on hard times.
Anyway, the books have, both collectively and individually, subcasts distinct from both the films and the rest of the EU. The only characters from either that appear are Han Solo and Chewbacca; anybody else might as well not exist. (Jabba the Hut[t] is briefly mentioned, but that's it. A mention of Han's "girl" is retconned into a character named Bria Tharen in the later Han Solo Trilogy.) Notables include:
Bollux and Blue Max. Literally inseparable, these droids are a sort of symbiotic pair that also radically contrast each other. Bollux is ancient, repeatedly upgraded but still obsolete, has been everywhere and done everything (almost literally-he reportedly served a unit captain during the Clone Wars, for instance), and while not brilliant, his experience grants him considerable insight despite him being intended to be a simple laborer. He is also driven by an unusually strong self-preservation instinct. Blue Max is, in a sense at least, Bollux's latest upgrade-Bollux was modified to conceal and protect Blue Max. Blue Max is more properly a sapient micro-computer, so-called because he's painted blue because blue paint is good for some reason or other, and Max because he's absolutely the most crammed-full-of-good-stuff little security cracking device ever made. Blue Max is essentially a brilliant newborn, without any experience but full of a lot of smarts, and as a result, he and Bollux make a strong team. Bollux and Blue Max appear in all three of the Han Solo Adventures.
Gallandro. Appearing in the second and third of the Adventures, Gallandro is something like an older, more heartless Han Solo. He's also the fastest gunman in the galaxy, or at least the fastest that Han Solo's ever met. He meets Han for the first time in the second book, and is his nemesis in the third.
Skynx. This alien is a Ruurian, which means he's essentially a giant sapient caterpillar. (Ruurian larvae are the useful, thinking members of society; adults are, as with most Earth insects, the ones that produce young but do little else.) Skynx is notable because, despite being totally nonviolent, he defeats Gallandro after Gallandro utterly whipped Han. And he did it easily.
There are others, but they're either less important or less entertaining.
Basically all the stories have the same general plot-Han's trying to make a killing, but his luck's against him. He tries to run valuable mineral water to a heavily polluted planet where everything tastes bad, but gets his tank punctured. He tries making money by showing primitive locals a holographic movie, but accidentally starts a religion, and gets in trouble when he picks out a different show. (That's a pretty big oops.) He hops on something that sounds lucrative, but it turns out to be slave-running, which has a mandatory death sentence attached to it. (He fights his way out of it.) So he has plenty of incentive to get mixed up in insane things such as political prisons, large criminal rings, and ancient hidden treasure.
A lot of it is pretty standard SF/Star Wars type fare, but there are a few moments that stand out. First is the infiltration of the prison Star's End and the result-he and others sneak in disguised as a band of entertainers, not knowing that the droid that they brought was supposed to be a gladiator robot (thus inadvertantly sentencing Bollux to death unless they can do something quickly), and finally breaching security by accidentally literally blasting the prison sky high. When I say literally, I mean literally-though it was an all-in-one-piece sky high. (Star's End was very well-armored-in fact, Han estimated it was the most expensive building he'd ever been in.)
The other part that really sticks out in my mind involves the Swimming People of Dellalt. (Disregard that cartoonish picture. Please.) The Swimming People, or merely Swimmers, are gigantic, immensely strong plesiosauroid lifeforms that speak excellent English. They are fully as smart as humans, though their worldview is entirely contained within a large lake and its near vicinity. They apparently had a limited ability to traverse solid ground, but their true environment was the water, where their strength allowed them to run a highly effective ferry service, in which they towed rafts.
The reason this part was so entertaining? Han and company got caught up in a Swimmer gang war. Also awesome was elder Swimmer Shazeen's remark to a female Swimmer who started speaking Swimmer hoot-talk to him in front of the group: "Use their language, woman." Something about that strikes me as incongruously hilarious.
At any rate, if you can find any of the individual Han Solo Adventures at a decent price, or the collective reprinting from more recently at a decent price, and you like Star Wars and novels, they're a pretty decent if somewhat incompatible read.