I am currently reading through the novels for Battletech. Starting with "Sword and the Dagger", I am now 17 books into it on "Main Event".
For the Era we are in, 3025, I suggest these:
Sword and the Dagger - Ardath Mayhar : The 31st Century begins
Decision at Thunder Rift - William H. Keith Jr.: Saga of the Grey Death Legion -- Book 1
Mercenary’s Star - William H. Keith Jr.: Saga of the Grey Death Legion -- Book 2
The Price of Glory - William H. Keith Jr. Saga of the Grey Death Legion -- Book 3
Warrior: En Guarde -Michael A. Stackpole Birth of the Federated Commonwealth--Book 1
Warrior: Riposte -Michael A. Stackpole Birth of the Federated Commonwealth--Book 2
Warrior: Coupe -Michael A. Stackpole Birth of the Federated Commonwealth--Book 3
I would also suggest:
Wolves on the Border - Robert N. Charrette
Heir to the Dragon - Robert N. Charrette
Though these two book start to push into the 3040s closing in on the Clan Invasion, they serve to establish a foundation for a lot of what is to come.
Here is the complete listing of all the books with exception of the newest Stackpole novella from the Kickstarter.
http://www.stargazerserv.com/csv/btech/battletech_novel_list.htm
Just as a fair warning, if you have older E-book versions of the titles, there are a nightmare of grammar and spelling mistakes. It felt that “Sword and the Dagger” was edited by a 3rd grader. Push past it, focus on the story and not the sentence structure and eventually it cleans up. By the warrior trilogy they found better editors and the errors reduce drastically. All the books are interconnected, even if by separate authors. Some have a better grip on the overall story of the universe where others sometimes seem to be faking it.
So happy reading. Enjoy the rich and deep lore this franchise has enjoyed since the 80s that has finally seem to be getting the attention it deserves.