This is an excellent series that has suspense and yet easy to digest. If you like the military SF sub genre you should also look at the Honor Harrington series by David Weber followed by the Safehold series and the March To The Sea series. Actually most stuff by David Weber is pretty good.
It's a space adventure with a likable heroine and plenty humour, but also some interesting character exploration.
Also has a good audio version by GraphicAudio.