Returning to the Lost Years example, I plan to read Dreadnaughts very soon. And I also want to read Mindshadow, to familiarize myself with J.M. Dillard's original characters (a security chief?). So, I'm wondering if I can get away with just reading Mindshadow, or will I get a more full effect from reading Dillard's other TOS novels before tackling The Lost Years?
I think each of Dillard's first three books introduces new characters and advances their relationships, so it'd probably be best to read Mindshadow, Demons, and Bloodthirst before TLY, although Bloodthirst and Dreadnought! are sort of awkward read close together because they both involve independent conspiracies among Starfleet flag officers.
Will I be okay with just Dreadnaught! before TLY, or should I also read Diane Carey's Battlestations as well to understand the Rittenhouse scandal?
The mention of Rittenhouse in TLY is in passing, and it doesn't address anything from Battlestations!, as far as I recall.
When it comes to Time For Yesterday, will I be okay with The Vulcan Academy Murders, or will the IDIC Epidemic be helpful to have been read?
I don't recally what aspects from those books are referred to in TFY, but it's probably just another minor detail rather than any specific events being referenced. Still, seeing as how The Vulcan Academy Murders and The IDIC Epidemic are consecutive adventures with continuing characters between them, it would make sense to read them together.