Hey, welcome. Thought I'd make some suggestions...I'll say a little about them so you can decide if it's something you'd like. While I like the novels better than the comics, most were less than I hoped for.
One exception was Tales of the Slayers, especially the sometimes tragic tales of the Cruciamentum (one of them featuring Nikki Wood), with more on what it's like to "awaken" as a vampire, along with what happens when a Slayer becomes a vampire (so much better than the comic of a Japanese Slayer turned vampire).
Tales of the Slayer is a series of prose short story anthologies. It was originally published by Simon & Schuster in the years of 2001–2004. The stories were centered in the figure of the Slayer through the years, as well as their relations with watchers, vampires, demons, as well as the...
buffy.fandom.com
One other I liked enough that I wish it had replaced Go Fish (it happens right around that time), one in which Spike's alienation from Angelus and wanting his revenge is made complete, what the Mayor was doing in season 2 (and his connection to Snyder...and his mother, now a demon), and Snyder's backstory, along with what it's like for a child vampire.
One Thing or Your Mother is a Buffy the Vampire Slayer novel. Written by Kirsten Beyer, it was originally published on March 3, 2008, by Simon Spotlight Entertainment. It's tough being a teenage Slayer. On the verge of failing her junior year — thanks to annoying Principal Snyder, who seems to...
buffy.fandom.com
There was one novel that I liked, but unlike the above examples, it felt too disconnected from both Buffy and Angel to me. Still, it was a fun crossover, IMO, and also more on Doyle (I can't remember and the book was stolen from me years ago, but I think Doyle's evil father, a member of the Scourge, is in it). Here it is:
Monster Island is a Crossover novel. Written by Christopher Golden and Thomas E. Sniegoski, it was originally published on March 1, 2003 by Pocket Books. Since he arrived in Los Angeles, Angel's mission has been to help the helpless. He has saved countless innocents in his city. However, one...
buffy.fandom.com
And I'm not a fan of the comics, a few exceptions (that take place in the TV seasons) aside, but even they didn't get me into the comic buying obsession (and I do buy comics, mostly manga, but Buffy comics don't normally do it for me, and it annoys me how outright, must be deliberate, misleading some are on the back about the content).
But this one is an exception...it feels like the TV show rather than like comics, and it links season 5 Buffy to 6 (how Willow got the ressurrection spell, how the Buffybot wasn't enough for Dawn, how Spike learned of the place to take the trials that would later get him a soul, etc):
en.wikipedia.org