Reddit mentions of Enterprise: The First Adventure

Okay, at your present Trek power level, I can recommend:

Final Frontier by Diane Carey

A TOS prequel surrounding George Samuel Kirk's involvement in the secret origins of the Constitution Class and interstellar espionage.

Terok Nor: Day of the Vipers by James Swallow

A DS9 prequel depicting the sociopolitical upheaval resulting from planet Bajor's first contact with Cardassia.

Both are ambitious stories that, as prequels, don't require you to have encyclopedic Trek knowledge to understand (as that Trek knowledge hasn't happened yet), yet they are told on such a grand scale that you'll come out of them with some great yarns under your belt and some decent Trek knowledge of your own to refer to should you get into any of the TV series. Final Frontier is a stand alone novel, but plugs into Enterprise: The First Adventure while Day of the Vipers is the first of a trilogy (though both are definitely the best).