Anime cuts out a lot of stuff, but if you didn't read the manga, you probably won't notice. You might say, "How did he come to that conclusion? Kind of a leap of faith, right?" but rest assured, it was explained in detail in the manga. The anime is sped up for more action (except the Yotsuba group arc).
Meanwhile, the manga tells you every single though Light and L ever have, and is quite explicit. Personally, I thought this was edge-of-your-seat entertaining as well, although some found it dry. It depends whether wall-of-text is an immediate turn off for you.